Cai Huikang started his football career when he joined the Genbao Football Academy in 2000 and was promoted to Shanghai SIPG's first team during the 2006 season. He became a regular as Shanghai won promotion to the second tier in the 2007 season. He scored his first goal for the club on 18 April 2008 in a 1-1 draw against Beijing Hongdeng. He lost his starting role during the 2011 season and was linked with a move to Guangdong Sunray Cave at the end of the season. Cai decided to stay at the club and appeared in 29 league matches in the 2012 season as Shanghai won the second tier league title and was subsequently promoted to the top FLIGHT.
