To solve the problem that uncertainties exsiting in the performance degradation data and failure threshold are always ignored in current methods, a new method of reliability analysis of performance degradation products based on blind number and GM(1, 1) model is proposed. Firstly, the blind number of degradation data and failure threshold is defined.The method of gray number ranking is used to optimize the confidence level of the blind number. The degree of reliability at the time of the measurement is calculated through blind number operation. Then, the parameter estimation of three-parameter Weibull distribution is carried out by using the GM(1, 1) modeling method, and the function of reliability degree is obtained. Finally, a case study on the degradation data of GaAs laser is provided to verify the effectiveness of the proposed method.The results illustrate the rationality, validity and high fitting precision of the proposed method, which can be used in engineering applications.