After the Cultural Revolution ended, the Chinese Communist Party (CCP) began to carry out large-scale rehabilitative work to overturn earlier unjust, false, and wrongful convictions. As part of this, from October 1976 to December 1978, more than 4,600 cadres who had been convicted during the Cultural Revolution were reinstated. After Hu Yaobang took office as head of the CCP Central Committee's Organization Department, work in this area accelerated. By the end of 1982, the rehabilitations were nearly finished.
After this large-scale rehabilitation, the Central Committee did a thorough reorganization of the cadre teams. This strengthened the reformers, led by Deng Xiaoping, while also attacking Hua Guofeng's Two-Whatevers faction. By 1980, Hua was gradually losing power, and China officially entered the era of the "Deng-Hu-Zhao system", in which Deng Xiaoping, Hu Yaobang, and Zhao Ziyang held power.
Reference: Yang Jisheng, "Political Struggles During the Age of Reform in China"