Choi participated on a modeling contest held by TVB at age 15. Two years later, she was a contestant in the 1991 Miss Hong Kong beauty pageant. During the semi-finals she placed first with an overall score of 483. She eventually finished as the second runner-up during the finals. She won the TVB Anniversary Award for Best Actress for her performance in Secret of the Heart (1998). Along with Maggie Cheung Ho-yee, Kenix Kwok, Flora Chan and Jessica Hsuan, Choi is known as one of the Top 5 "Fa Dans" (term used for actresses with high popularity) of TVB from the mid-1990s to mid-2000s. In 2009, she starred in Rebellion as a triad gang leader who chain-smokes and curses, a different type of role for Ada.