For the actual evaluation of the synthetic brigade equipment support capability， considering the fuzziness and randomness of the standard interval of index grade in the evaluation， a synthetic brigade equipment support capability evaluation model based on extension cloud is proposed. The evaluation index system of synthetic brigade equipment support capability is constructed through the systematic analysis of synthetic brigade equipment support task. The weight of each evaluation index is determined by the comprehensive weighting method combining AHP and Entropy method. Considering the advantages of qualitative and quantitative analysis of matter-element model and the characteristics of uncertainty reasoning of cloud assessment model， the extension cloud model of synthetic brigade equipment support capability assessment is constructed， and the confidence information of assessment results is given， the extended cloud model of synthetic brigade equipment support capability evaluation is constructed， and the confidence information of evaluation results is given. The method is proved to be scientific and effective by an example.