Cai Dongdong is a 19-year-old professional football player from CHN. He currently plays for Liaoning Tieren U20, wearing the number 33 shirt. He plays primarily as a Defender.

Throughout the Chinese U17 League 2025, Cai Dongdong featured in 7 matches, averaging 2.3 tackles, 1.1 interceptions, and 2.1 clearances per game, while blocking 0 shots per game.