Disclosed in the present disclosure is a frame mechanism and a board card module. The frame mechanism includes a frame body and a fixing bracket, a baffle piece of the frame body is configured to fix a front end of the board card, the fixing bracket moves relative to the frame body, and the fixing bracket fixes a rear end of the board card. A first limiting portion of the frame body and a second limiting portion of the fixing bracket form a limit fit to lock the fixing bracket onto the frame body, when the fixing bracket moves, the first limiting portion and the second limiting portion are in an unlocked state, the fixed bracket rotates relative to the frame body.