A card connector includes an insulating holder base having a first slideway and a second slideway formed on both sides of a plug-in space therein, a terminal set with multiple conductive terminals set in the plug-in space, and a push-push mechanism including a main sliding seat and an auxiliary sliding seat independently structured and respectively set in the first slideway and the second slideway. The main sliding seat is provided with a first resisting arm, and a cyclic guide groove and a guide rod for sliding positioning. The auxiliary sliding seat has a second resisting arm. The first resisting arm and the second resisting arm are used for resisting and moving a combined structure of a preset SIM card and a tray, so that when the main sliding seat and the auxiliary sliding seat are moving, the main sliding seat has a greater resistance than the auxiliary sliding seat.