Safety protection device and method for battery test system

A safety protection method for a battery test system, comprising:

• using a system device to detect in real time a plurality of sets of detection information of a battery pack and to perform a plurality of determinations on the plurality of sets of detection information to obtain a plurality of sets of determination information, and the system device respectively switching an alternating current (AC) changeover switch and a direct current (DC) changeover switch according to the plurality of sets of determination information, wherein the system device is coupled to a load device, the AC changeover switch is coupled between an AC source and the system device, and the DC changeover switch is coupled between the battery pack and the system device;
• and
• enabling a measurement and automation unit and a programmable control unit of the system device to achieve a synchronous counter function in between by using a pulse width modulation (PWM) signal, and when abnormality occurs in the measurement and automation unit, the programmable control unit transmits a digital signal to the AC changeover switch to perform disconnection.