The invention discloses a performance testing device for a single-phase motor power saver. The device comprises an installation machine box, and a liquid crystal display and function selection keys are embedded in the outer surface of the installation machine box; an integrated circuit board is installed in the installation machine box, and a main control chip is welded to the integrated circuit board, wherein the data input end of the main control chip is connected with a zero-sequence current detection module, and the command output end of the main control chip is connected with a circuit breaker protector and a sound-light alarm module; the zero-sequence current detection module comprises an external probe; the input end of the external probe is connected with an alligator clip, and thealligator clip is clamped on a circuit to be detected; the output end of the external probe is connected with a zero-sequence current transformer, and the output end of the zero-sequence current transformer is connected with a linear operational amplifier, wherein the linear operational amplifier is further connected with a voltage comparator and an analog-to-digital conversion circuit. The electric leakage phenomenon can be effectively detected, an alarm is given in time, the circuit protection is achieved at the same time, and the probability of safety accidents is reduced.