1in March, 947, Chiang Kai-shek changed the full-scale attack on the liberated areas into a key attack, one of which was the Shensi-kansu-ningsia border region, with the Central Committee of the Communist Party of China and the People's Liberation Army headquarters in Yan 'an bearing the brunt. At that time, there were 230,000 Kuomintang troops in the northwest battlefield, mainly the troops under the command of Hu Zongnan, the commander of the L Theater and Chiang Kai-shek's own general. They are well-equipped and domineering. The Northwest Field Army of the People's Liberation Army has less than 30,000 troops, which is extremely poorly equipped and difficult to supply.

On March 1947 and 13, Hu Zongnan reorganized the 1 Army and 15 Brigade, belonging to six integrated divisions in 29 army, with a total of about 140,000 people, starting from Luochuan and Yichuan respectively and pointing directly at Yan 'an. Peng deployed Yan 'an Defence War as Vice Chairmen of the CPC Central Military Commission and Chief of General Staff to cover the transfer of the central organs and the PLA headquarters. The teaching brigade, the third garrison brigade and the first column of the Northwest Field Army built deep positions in Linzhen Town, Jinpenwan, Niuwu, Teahouse and other places south of Yan 'an, relying on favorable terrain to resist. The Kuomintang troops attacked Yan 'an with nearly 100 planes and a large number of artillery. The Northwest Field Army fought bravely under extremely difficult circumstances and fought back one after another.

1947 March 16, the Central Military Commission of the Communist Party of China (CPC) issued an order, and Peng became the commander-in-chief of the northwest field army, taking on the task of directly commanding the northwest battlefield operations. 1947, 18 In March, the Kuomintang troops had arrived at the gates of Yan 'an, and it was not until the evening that the Central Committee of the Communist Party of China, Zhu De, Ren and the People's Liberation Army left Yan 'an. The battle of Yan 'an lasted seven days and seven nights.

On March 1947, Kuomintang troops occupied Yan 'an. When he left, he said to Peng, "Chiang Kai-shek hit himself on the foot and attacked Yan 'an. At least a year, more than two years, we all have to come back. "