In order to solve the problem that it is difficult to determine the minimum sample size for the reliability life test of an accelerometer, based on the reliability statistical inference theory and the life distribution characteristics of mechanical and electrical products, a minimum sample size sampling method suitable for engineering application is proposed, which combines the original data modification, distribution model establishment with sampling method design.It is obtained through this method that the sample size of the accelerometer for reliability life test is 11, which is experimentally verified.The results show that the relative error between the prior parameter value calculated by the sampling method and the original value is less than 1.5%, which can meet the engineering application.