The invention provides a module test device and a test method thereof for testing a first connector of a mainboard, wherein the first connector is provided with a plurality of first pins. The module test device is coupled with a computer device and a multimeter and comprises a second connector with a plurality of second pins, a switch unit, a controller and a first pinboard. The module test device is directly inserted with a first connector or is inserted on the first connector through the first pinboard. The second connector is inserted on the first connector. The second pins are respectively coupled to first pins. One end of the first pinboard is adapted to the second connector, while the other end is adapted to the first connector. The switch unit is coupled with the second pins. The controller is coupled with the switch unit, receives a control signal derived from the computer device and controls the operation of the switch unit according to the control signal so that the test device is matched with the multimeter to test the first connector; and the multimeter provides a test value to the computer device.