After the Red First and Fourth Fronts crossed the meadows, they carried out the Battle of Baoza and opened the road to Gannan, but then Zhang Guotao changed his mind and insisted that the Red Fourth Fronts go south, so in mid-September 1935, the red fourth front troops that had already crossed the grassland went south from Aba, Baoza, Banyou and other places, and once again gathered through the grassland to the Dajinchuan area.
On October 24, 1935, the Red Fourth Front crossed the Jiajin Mountain and advanced southward, and at first the battle was relatively smooth, and In the battle to capture Tianquan, Lushan, Baoxing, etc., Liu Xiang's elite "model division" was also defeated. After consecutive victories, the Red Fourth Front decided to continue its attack in the direction of Mingshan and Qionglai.
The Sichuan army has always been a defeated general under the Red Fourth Front, and in the sichuan-Shaanxi base area against the three-way siege, the anti-six-way siege and other battles, the Sichuan army lost more than 100,000 yuan, so the contempt for the Sichuan army is common, but many Red Army commanders and fighters have overlooked one point, that is, the famous mountains and Qionglai further down is the rich west Sichuan Plain, which is Liu Xiang's "granary" and "old nest", so he will do his best to defend west Sichuan.
On November 16, the Red Fourth Front captured the military town of Baizhangguan, which was the only place for Ya'an to pass through Chengdu, and Liu Xiang concentrated all his elite regiments of more than 80 regiments to advance towards Baizhangguan, and he issued a death order that no matter how much the price was, it was necessary to retake this important place, and anyone who did not fight in the front would be shot on the spot.
On November 19, Liu Xiang's Sichuan army launched a group charge against Baizhangguan from the eastern, northern, and southern sides, while the Nanjing side also sent aircraft to support the operation.
The battle plan of the Red Fourth Front was to resist the Sichuan army's attack on the baizhangguan front, and then defend and counterattack just like the previous Wanyuan defense battle, but at this time and time, the Sichuan army's combat will at this time was significantly higher than before, coupled with Liu Xiang's desperate efforts to send all the elites, the Red Army's battle on the front line was very arduous.
Founding General Chen Xilian was then the commander of the Red 10th Division of the Red Fourth Front, and he thought that the Battle of Baizhangguan was the most brutal battle he experienced during the Red Army period, Chen Xilian recalled: "We placed hundreds of machine guns on the arc-shaped positions in the Baizhangguan area for more than ten miles to strafe the enemy, knocked out a batch, and came up another batch, and these Sichuan troops were like leeks, cutting a stubble and growing a stubble. ”
The Sichuan army braved the machine guns on the Red Army's position to advance, although the entire company and the whole battalion were swept down, but because of the absolute superiority in manpower, it still kept launching a group charge, while the Red Fourth Front, although there were more machine guns, lacked artillery and anti-aircraft weapons, and under the bombardment of enemy aircraft and artillery, the casualties of the Red Army holding the position were also very large.
The Red Fourth Front and Liu Xiang's Sichuan Army fought fiercely for seven days and seven nights on the baizhangguan front, the Sichuan army suffered fifteen thousand casualties, and the red army suffered nearly ten thousand casualties, although the position was temporarily held, but this war of attrition was obviously not worth the loss, at this time the red fourth front army was also facing a dangerous situation, xue Yuezheng in the south led the strength of 6 divisions to press up and prepare to take advantage of the fact that the Red Army and the Sichuan army were both defeated and wounded, in this case it was impossible to hold on to the Baizhang pass, and the general headquarters of the front army was forced to order the Red Army to take the initiative to withdraw from the position. Transferred to the Tianquan County area of Ya'an.
On the way to the red fourth front, the red fourth army and the xue yuebu in the south encountered a fierce battle and suffered heavy losses, and the red thirty-third army also exchanged fire with the enemy Li Baobingbu from the east, and it was impossible to go south or east, and the red fourth front had to cross the Jiajin Mountain again.
In April 1936, the Red Fourth Front army came to the Ganzi area and was reorganized here, with Xu Xiangqian, commander-in-chief of the headquarters of the Front Army, Chen Changhao, political commissar, and Wang Shusheng, deputy commander-in-chief, under the jurisdiction of five armies, namely, the Red Fourth Army (commander Chen Zaidao, political commissar Wang Hongkun), the Red Fifth Army (commander Dong Zhentang, political commissar Huang Chao), the Red Ninth Army (commander Sun Yuqing, political commissar Chen Haisong), the Red Thirty Army (commander Cheng Shicai, political commissar Li Xiannian), the Red Thirty-first Army (concurrently served by military commander Wang Shusheng, political commissar Zhou Chunquan), the Red Thirty-second Army (commander Luo Binghui, Political Commissar Li Ganhui), in addition to the directly administered cavalry division (division commander Xu Shiyou), the Red Army University and other institutions.
Although the Red Fourth Front still had five corps after the reorganization of Ganzi, the total strength of the red fourth front had been sharply reduced from more than 80,000 people when it went south to more than 40,000 people, and the facts proved that Zhang Guotao's move to the south was wrong.