A three dimensional (3D) detection device has a detection supporter base to be disposed on a transmission device, ultrasonic transceiver modules disposed on at least one inner base surface of the detection supporter base and a controller. When a tested object is transmitted by the transmission device and then enters the detection supporter base, the ultrasonic transceiver modules emit ultrasonic signals to the tested object, and the tested object reflects the ultrasonic signals to the ultrasonic transceiver modules. The ultrasonic transceiver modules generate detection signals according to the reflected ultrasonic signals. The detection signals are sent to the controller, and the controller generates an ultrasonic image corresponding to a tested object according to the detection signals, and then compares the ultrasonic image to a pre-established original 3D image, so to achieve a surface detection objective.