Equipment manufacturing units often have the problem of credit deficiency in equipment development and procurement contracts. It is significant to carry out scientific assessment of credibility. Use explanation structure model to established index system of equipment contractor performance reputation evaluation, and gave grey clustering degree evaluation model based on triangle whitenization weight function. Then used example to analyze and verify the method. The verification results show that the method is simple and effective and it can give quantitative analysis reference for army evaluating reputation of equipment manufacturing unit.