The utility model discloses a short-circuit arc fault generating device. The device comprises a voltage output terminal, an adjustable resistor, a current peak value detector, a delayer, a foam extinguisher, and a cabinet with an observation cover; wherein the voltage output terminal, the adjustable resistor, and the current peak value detector are orderly serially connected to form a circuit so as to form a short-circuit arc fault; the current peak value detector is connected to the delayer, and the delayer is connected to the foam extinguisher. When the current peak value detector detects that the current in the circuit exceeds the limit value of the current peak value, the device immediately starts the foam extinguisher through the delayer to deal with the short-circuit arc fault. The sample cabinet with an enclosed structure can effectively guarantee the safety for testers.