In the Romance of the Three Kingdoms, when Wei Yan killed The Taishou Han Xuan of Changsha and defected to Liu Bei, Zhuge Liang said that he had killed his lord, belonged to the disloyal and unrighteous, and had a backbone in the back of his head, and would definitely rebel in the future, and would drag him out and cut him down.
Later, Liu Bei personally interceded, saying that he was worried that killing Wei Yan would hurt the heart of the descendant, and Zhuge Liang opened his eyes and spared his life. However, Zhuge Liang still warned Wei Yan not to have any different intentions in the future, otherwise he would be taken to the first rank.
Zhuge Liang's words are not just talk. When his last Northern Expedition recurred in Wuzhangyuan's old illness and he could not afford to be ill, Zhuge Liang expected that Wei Yan would start a rebellion, so before his death, he secretly ordered Ma Dai to pretend to cooperate with Wei Yan, approach the other party, and then find an opportunity to kill him. In the end, Wei Yan was beheaded by Ma Dai under The City of Southern Zheng.
Because the "Romance of the Three Kingdoms" was widely circulated in the folk, many people, after watching the speech, thought that Zhuge Liang thought that Wei Yan would rebel from the beginning, and was extremely uneasy about him, and finally designed to kill Wei Yan.

However, this is only the statement in the novel, and the death of Wei Yan in history has nothing to do with Zhuge Liang. Moreover, in fact, Zhuge Liang was very tolerant of Wei Yan before his death, and even had some protection.
According to the Chronicle of the Three Kingdoms, the historical Wei Yan has always been Liu Bei's subordinate, not Liu Bei only defected to him when he was conquering the four counties of Jingnan, so naturally there could be no matter of killing his old lord.
Moreover, in the early days, Wei Yan's status was low, until he followed Liu Bei into Sichuan, and later performed in the Battle of Yizhou with Liu Zhang, and was able to be awarded the title of General of Yamen after Liu Bei pacified Yizhou and came to prominence. After the Battle of Hanzhong, Liu Bei promoted Wei Yan to the rank of General of Zhenyuan, Hanzhong Taishou, and Zhenshou Hanzhong, making him one of the backbone of the Shu Han clique.
With the part of the first lord into Shu, a number of battle achievements, the general of the Qianya gate ... The ancestor was Bayan as the general of Zhenyuan in Hanzhong, and led Hanzhong Taishou to shock the army.
During this period, Zhuge Liang mainly stayed behind in the rear to manage local affairs and handle government affairs, rarely involved military affairs, and had almost no intersection with Wei Yan, so it is not clear how Zhuge Liang's attitude towards Wei Yan was.
By the time Liu Bei died and Zhuge Liang was in charge of the military and political power of the Shu Han Dynasty, not only guan Yu, Zhang Fei, Huang Zhong, and other senior generals had already died one after another, but many of the new generation such as Feng Xi, Zhang Nan, and Fu Tong had also died in Yiling, and the talents that Zhuge Liang could use were very limited, and Wei Yan's level of generals naturally became the object of reliance.
Therefore, during Zhuge Liang's Northern Expedition, Wei Yan was appointed as the Commander of the Xiang Dynasty and the Assassin of Liangzhou, and fought as a pioneer many times, and later promoted to the rank of former military division and the General of the Western Expedition for his merits, becoming the highest-ranking military general in the Shu Han army, which shows the importance Zhuge Liang placed on Wei Yan.
Moreover, Wei Yan was arrogant and arrogant, difficult to get along with others, and often quarreled, in which case Zhuge Liang was generally extremely tolerant of him.
For example, the cheqi general Liu Yan was a veteran figure who followed Liu Bei for many years, and in terms of official position alone, he was the second most important person in Shu Han after Zhuge Liang. As a result, when Liu Yan and Wei Yan had an argument over the incident, Zhuge Liang asked Liu Yan to take the initiative to apologize.
There was also the long history Yang Yi who was not accustomed to Wei Yan's arrogance and never pretended to be angry, resulting in an extremely stiff relationship between the two, and the situation was the same as water and fire, and there were many disputes. During a meeting, the two quarreled for some reason, and Wei Yan drew his sword in anger and threatened to kill the other. For such an arrogant move, Zhuge Liang did not punish him, but tried to reconcile the relationship between Wei Yan and Yang Yi.
Even when Zhuge Liang was dying of illness, it was expected that Wei Yan might disobey the order and refuse to withdraw his troops. He also just asked Yang Yi and others to stop caring about Wei Yan and withdraw their troops on their own. Obviously, Zhuge Liang was still extremely tolerant of Wei Yan.
Of course, some people may think that Zhuge Liang used Wei Yan so much, but it was only because the Shu Han talent withered away and he had no general to use it, so he had to do so. When Wei Yan really suggested that he lead the army alone, Zhuge Liang did not agree, which was not really reusing him.
Yan Every time he came out, he wanted to invite tens of thousands of soldiers, and liang would meet at Tongguan, such as The story of Han Xin, and the bright system was not allowed. Yan often said that the light was timid, and the hatred of oneself was inexhaustible.
However, we must see that in history, although Wei Yan is famous for his bravery, he is more reckless in his work. For example, after Zhuge Liang's death, Wei Yan rebelled and eventually lost and died, which is a typical example, and it is not suitable for leading the army alone. Therefore, Zhuge Liang did not let him lead the army alone, not because he hated Wei Yan.
If Zhuge Liang really didn't like Wei Yan, then before he died, he could completely summon Wei Yan to the account to kill in the name of entrusting the aftermath, and there was no need to go around in a big circle for Ma Dai to kill. After all, in real history, no matter how much a warrior can fight, it is impossible to deal with dozens of knife and axemen without preparation.
Therefore, from a comprehensive point of view, Zhuge Liang is actually quite important to Wei Yan, and he is very tolerant of him, and there is no possibility of wanting to kill Wei Yan. Wei Yan's death in the end was mainly because he not only disobeyed Zhuge Liang's will, but also raised an army to attack Yang Yi, which was like a rebellion, and he embarked on a desperate road and had nothing to do with Zhuge Liang.