Leakage circuit breakers are important terminal protection appliances in low-voltage power distribution systems. They play a major role in preventing leakage accidents and protecting the lives and property of power users. Once they fail, they will cause serious harm to the power grid system and people"s lives and property. Because the leakage circuit breaker has the characteristics of high reliability and long service life, the reliability test of normal stress can not obtain sufficient data for reliability evaluation in a short time. A step acceleration degradation test scheme for leakage circuit breaker is proposed.It analyzes the performance degradation law of leakage circuit breakers and carries out reliability prediction.Firstly, it determines the acceleration model and the acceleration stress. According to the preliminary experiment, the characteristic parameters are determined. Then, considering the failure mechanism of the leakage circuit breaker, the test sample and the efficiency, it selects the appropriate stress level, test period, failure threshold, etc.The test parameters, finally the degradation of the residual operating current value of the leakage circuit breaker during the experiment, the Degeneration model is established by the Wiener process, and the probability density function and reliability function of the remaining life of the leakage circuit breaker are obtained.