In August of the second year of the Apocalypse (1622), he went to Liaodong to take office (Shanhaiguan). Let the former generals of Jizhou, Liaodong, Tianjin, Dengzhou, and Laizhou supervise everywhere, and their actions when they see opportunities do not have to be restricted by others. Yan Mingtai was used as the inspector of Liaodong Province, and Lu Shanji and Wang Zegu were used as Zanhua (chief of staff). Let Jiang Yingzhao formulate military establishments, let Yuan Chonghuan build barracks, Li Bingcheng train firearms and equipment, Lu Shanji and Wang Zegu handle military supplies, Shen Di and Du Yingfang repair armor battles, Sun Yuanhua build forts, Song Xian and Cheng Lun buy military horses, harvest trees, Zu Dashou assists Jinguan to guard Juehua Island (now Chrysanthemum Island), Chen Zhizhu and Zhao Lead teach to guard Qiantun (present-day Suizhong Qianwei Town), Lu Zhijia saves refugees, and Yang Yingqian recruits Liao people to form an army.
Sun Chengzong found that the soldiers who had previously been closed were undisciplined, and that there were a large number of people who did not meet the conditions to pretend to be paid. Therefore, after Sun Chengzong's military parade, he sent back soldiers who did not meet the conditions in Henan, Zhending (present-day Zhengding) and other places. The refugees rescued by Lu Zhijia were stationed in Qiantun, and the Liao army recruited by Yang Yingqian went to Zhenshou Ningyuan, asked the DPRK to support Liaodong, and rewarded Mao Wenlong in Dongjiang Town to let him guard on all sides. He also ordered Shen Yourong to enter Hiroshima (present-day Hiroshima Town, Changhai County). At this time, Jiang Yingzhao was impeached, and Sun Chengzong requested that Wan Shilong be replaced, and You Shilu and Wang Shiqin were made the marshals of the north and south, at the dispatch of Ma Shilong, and Zhu Youxue followed Sun Chengzong's advice and gave Ma Shilong the sword above.
Inspector Yuan Keli and Sun Chengzong were both examiners of the Heavenly Apocalypse Second Year Temple Examination, and the Manchus crouched down during the liao period. Sun Chengzong attached great importance to Yuan Keli in the Liao Coastal Defense Commission. In reply to Yuan Jie Huan Dengfu said: "After reading, first be great, unveil the sun and the moon, walk in the middle of the sky and penetrate the bottom, it is very delicious, you can spread the four bodies, and you can pay tribute to the country."
Some people in the imperial court emphasized the mountains and seas over the coast, and some even requested the dismissal of the Inspector of Dengcai. However, Sun Chengzong believed that "if the Liao is restored, it will be invested in the sea." "I ask the emperor to take this part of the flood land of the two towns, give it to the soldiers of Dengzhen, and the fuchen (Yuan Keli) of Denglai to take care of it, and still order the two towns to be tempered, and all the soldiers and horses should pay money and grain, collect and dispatch, and return the crime of preventing and suppressing merit to the manager."
After Sun Chengzong went to Liaodong, the castration party monopolized the real power of the imperial court. Wei Zhongxian often sent his henchmen Liu Chao, Hu Liangfu, and Ji Yong to patrol the border passes. Ostensibly a comforting unit, it was actually spying on military intelligence and spying on Sun Chengzong. He wrote to Zhu Youjian and said that he could not let the eunuchs supervise the army. Sun Chengzong did not take the emissaries seriously, and came to Liaodong only with tea to entertain.
Due to the provocation of the eunuch party, some Liaodong generals proposed to retreat to Shanhaiguan. Ma Shilong suggested that Sun Chengzong of Shouzhong Houshou (present-day Suizhong County) firmly advocate defending Ningyuan (present-day Xingcheng), allowing Zu Dashou to build a defensive project, and having Yuan Chonghuan and Man Gui garrison Ningyuan (which proved to be true in practice). Sun Chengzong was also stationed in Ningyuan.
In the fourth year of the Apocalypse (1624), under the care of Sun Chengzong, Ningyuan City was restored. It can be said that it is an indestructible city in western Liaoning (now well preserved). The Liaodong Governor Moved to Ningyuan. Later, Nurhaci attacked Ningyuan City without capturing it, and he was injured and depressed and died.