The striker spent last season on loan at Newcastle and links up again with manager Rafael Benitez, who left St James's Park for China last month.
Rondon joined West Brom in 2015, making 120 appearances for the club and scoring 28 goals before their relegation from the Premier League at the end of the 2017/18 campaign.
The Venezuela international made 33 appearances for Newcastle last season, scoring 12 goals.
Rondon joins former Napoli captain Marek Hamsik and Belgium winger Yannick Carrasco on the books at Dalian Yifang.
"The club wishes Salomon and his family all the very best in the future," read a West Brom statement.