The deal was originally announced in August after former chairman Jeremy Peace agreed to sell the club to the group led by Guochuan Lai.
"It has been a tremendous privilege to lead the Albion," Peace said in a statement. "I am proud that 11 of my 15 seasons as Chairman have been spent in the Premier League whilst three others brought automatic promotion from the (second tier) Championship."
Chinese companies are increasingly interested in buying stakes in European soccer clubs not only as good investments but also as a way to help President Xi Jinping's bid to raise the profile of the sport in China.
Last month, Chinese investment groups announced deals to buy Italy's AC Milan and second-tier French side Auxerre.
Other recent recipients of Chinese backing include Aston Villa, Wolverhampton Wanderers and Inter Milan while Manchester City and Atletico Madrid have significant minority investments from the country.
“I’m delighted to complete the acquisition and to become the next steward of the club," Lai added in the statement.
(Reporting by Toby Davis; editing by Clare Lovell)
