Export posters like this one, with Western subtitles, were shipped to Europe and the United States in large numbers, and distributed by Maoist groups there. They were very popular among left-wing students. The man on the left looks very much like Chen Yonggui, leader of the agricultural model village Dazhai.
This poster was originally published May 1970 by the Shanghai Publishing Revolution Group (上海市出版革命组出版, Shanghaishi chuban gemingzu, print nr. 3-57(1)24).