For the failure analysis of products with high reliability requirements, it is often encountered that the failure data cannot be obtained for a long period of time. Based on this situation, the reliability evaluation method of zero-failure data has been developed and achieved certain results in the actual engineering application process. In this paper, when the product life is subject to Weibull distribution, the reliability evaluation of the bearings is obtained according to the optimal confidence limit evaluation method. A method to extend the application of optimal confidence limits is proposed. Combined with the results of numerical simulation case studies, the results indicate that the type of zero-failure data grouping has a direct impact on the reliability evaluation results, and the reliability estimate is closer to the real situation in a certain period of mission time.