The reliability evaluation of the product under the interaction of internal performance degradation and load shock is considered comprehensively. Owing to the intensity of resist maximum load shock gradually decreases of the products under performance degradation. Compared with the traditional constant intensity threshold, the reliability analysis model with the stochastic intensity threshold is established. Assuming the production performance present multi-state process according to the number of shock, the reliability evaluation model with the constant intensity threshold and random intensity threshold of products were obtained, and the reliability of products is described by using Copula theory under the dependent failure of the internal performance degradation and load shocks with interaction.Finally, the internal degradation process of products is described by using normal distribution. The product reliability under two kinds of intensity threshold is analyzed, and the model is verified.