China is expected to launch the crewed spacecraft Shenzhou-12 at 1.22GMT on 17 June in Jiuquan in northwestern Gansu province, an official at the China Manned Space agency said.
The astronauts were Nie Haisheng, 56, Liu Boming, 54, and Tang Hongbo, 45, said Ji Qiming, assistant director at the China Manned Space Agency, in a press conference in Jiuquan.
Nie, a native of central Hubei province and a former air force pilot, will lead the mission. He will be the oldest Chinese astronaut to go into space.
Shenzhou-12, meaning "Divine Vessel", will be the third of 11 missions needed to complete China's space station by the end of 2022. China began construction of the station in April with the launch of Tianhe, the first and largest of three modules.
The Shenzhou-12 crew is to live on the Tianhe, which means "Harmony of the Heavens", a cylinder 16.6m-long and 4.2m in diameter, for three months.
The Shenzhou-12 will be Nie's third space outing, after the Shenzhou-6 mission in 2005 and the Shenzhou-10 mission in 2013.
It will be Liu's second mission to space and Tang's first.
Chinese astronauts have had a comparatively low international profile.