The study focuses on the verification of the equipment maintainability indexes in small-sample tests with multi-source pre-test information.For the situation when the pre-test information comes from different sources, an equipment maintainability verification method in small-sample conditions under the mixed pre-test distribution is proposed.The pre-test distribution of each pre-test information is determined by using Bootstrap method.The weighted credibility fusion method based on the quality factors is improved, and the mean credibility weight factor and the sample-size credibility weight factor are defined.The weight calculation results are more scientific and reasonable.A Bayes sequential probability ratio method under the mixed pre-test distribution is derived.The MTTR is verified through the maintainability verification test of an armored equipment.The results show that the proposed method can effectively verify whether the indexes of equipment maintainability can meet the design requirements.