The invention discloses a water resistance test device, comprising a tank body and a tank cover, wherein an insulated trough that can be extracted is arranged in the tank body, the insulated trough is filled with an electrolyte, and a fixed electrode is arranged at the bottom of the insulated trough; a power supply, a push rod motor, a voltmeter, an ampere meter, a test terminal and a receiving device are integrated on one side of the upper end of the tank body; the push rod motor is supplied with power by the power supply, the output end of the push rod motor is connected with a movable electrode, and the movable electrode stretches into the electrolyte and can move up and down under the drive of the push rod motor; the power supply, the fixed electrode and the mobile electrode form a circuit; the voltmeter is connected in parallel to the circuit, the ampere meter is connected in series to the circuit, an external circuit breaker is connected to the test terminal, and the circuit breaker is connected in parallel to the circuit. The device realizes accurate control on the circuit operated by the circuit breaker, simultaneously effectively isolates the high-voltage circuit, avoids accidental electric shock, greatly improves the safety, and can be universally popularized and applied inside systems and user substations.