The three astronauts from the Shenzhou-20 mission flew to the Tiangong space station in April and were finishing their six-month rotation. The group consists of team leader Chen Dong, fighter pilot Chen Zhongrui and engineer Wang Jie.
Their replacements on the Shenzhou-21 mission had successfully docked onto the space station on Saturday.
China has made steady progress with its space program since 2003. It has built its own space station and has a goal of landing a person on the moon by 2030.