A connector module (100) includes a base (1) including a front face (101), a rear face (102) opposite to the front face, a top face (103) connecting the front face and the rear face, and a mounting slot (104) extending through the front face and the rear face; a first connector assembly (2) mounted on the base; a second connector assembly (3) mounted on the base through the mounting slot along a rear to front direction, and extending beyond the front face for being mated with a mating connector; and a block member (4) mounted on the base with a portion projected into the mounting slot to block a rear end of the second connector assembly to prevent the second connector assembly from withdrawing from the base.