Abstract: This paper presents a method of structural damage life prediction and reliability evaluation based on stochastic Wiener process. Firstly, the random Wiener process is used to build the performance degradation model and life prediction model of the product; secondly, the parameters of the model are estimated by the unbiased parameter estimation method combined with the least square principle based on the performance degradation test data; then the life prediction and reliability evaluation of the product are carried out by the established model; finally, a gear is taken as an example to verify the proposed model applicability and effectiveness of the proposed method.