The poster depicts a battle during the final stages of Chinese Civil War. PLA soldiers chase Guomindang soldiers, force them to surrender or are about to kill them (as on the tank on the left).
In 2021, a Chinese user on shz100.com commented that this could be a scene from the Liaoshen campaign (辽沈会战), September-November 1948, when the PLA encircled and annihilated Liao Yaoxiang's Ninth Corps of the Guomindang army in the Hujia shack area battle. This could be true, it could also be a more generic representation.