A safety protection device for a battery test system includes a system device, an alternating current changeover switch and a direct current changeover switch. The system device is coupled to a load device. One terminal of the AC changeover switch is coupled to an AC source, the other terminal of the AC changeover switch is coupled to the system device. One terminal of the DC changeover switch is coupled to a battery pack, the other terminal of the DC changeover switch is coupled to the system device. The system device detects in real time a plurality of sets of detection information of the battery pack, performs a plurality of determinations on the plurality of sets of detection information to obtain a plurality of sets of determination information. The system device respectively switches the AC changeover switch and DC changeover switch according to the plurality of sets of determination information.