Upon the end of the war, Sun Yu began preparing for his most important production yet, a biographical epic of the Qing Dynasty educator, Wu Xun, who spread literacy among the common people. Sun's last major work, "The Life of Wu Xun" was made with the Kunlun Film Company and starred one of the top actors of the day, Zhao Dan, in the titular role. Shortly after its release, however, "The Life of Wu Xun" was personally denounced by Mao Zedong. In the "People's Daily" Mao attacked Wu Xun as a liberal whose literacy programs implied that revolution was not necessary. The flurry of criticism that Mao's denunciation triggered was the "first major politico-ideological campaign" of the post-1949 revolution, and its effects were immediate. As a result, Sun Yu's reputation was soon in ruins, and his career effectively stalled. Sun Yu would go on to direct only a handful of titles over the next twenty years. In 1985, thirty-five years after the release of "The Life of Wuxun", members of the Chinese politburo finally admitted that Mao's campaign, and the criticisms that it instigated against the film, was essentially baseless.