The main force of the Central Red Army cleverly captured Jiaoping Ferry on May 3, and then calmly crossed the Jinsha River for seven days and nights.Just two days later, the Kuomintang army trying to intercept the Red Army on the south bank of the Jinsha River arrived, only to find that the Central Red Army had already crossed the river and entered Sichuan.Immediately afterwards, on May 12, the Red Army held the crucial 6th Political Bureau meeting of the Central Committee of the Communist Party of China in Huili, Sichuan. This meeting further confirmed Mao Zedong's command authority and made an important decision to immediately go north., and at the same time joined up with the Fourth Red Army.

Xu Zhengye and Qu Xiangdong assisted Cai Zejuan in obtaining and deciphering Huang Jibi's password, and the news spread quickly.Soon, the second station intercepted the new secret message and instructed the troops from all parties to prevent Zhu Mao from going north in Dadu River and other places, and to launch an encirclement and annihilation campaign.In response, the Central Red Army responded quickly and successfully attacked the enemy at Anshun Pass. Then they decisively divided their forces into two groups to quickly seize the Luding Bridge, successfully breaking the enemy's encirclement and suppression plan.

With the help of timely and accurate intelligence, the Central Red Army and the Fourth Front Army of the Red Army led by Li Xiannian successfully joined forces in Maogong. The joining forces of the two armies created extremely favorable conditions for the new revolutionary situation and greatly improved the morale of the commanders and soldiers.The subsequent Lianghekou Conference determined the strategic direction for the two armies to move north together. However, Zhang Guotao had a hidden conspiracy. Although he agreed at the meeting, he had other plans in private.

Faced with the complex situation, the Red 1st and 4th Red Front armies made decisions and chose the strategy of going north via Songpan Grassland.After going through hardships, Cai Zejun's right army finally got out of the woods, but the left army failed to move north as expected.After the Battle of Baozuo, facing the approach of the Kuomintang troops, the Red Army had to make major adjustments. In the process, some of the troops split due to various reasons, which brought new problems and challenges to the entire war situation.