On the basis of the fuzzy mathematics theory and the evidence theory, an assessment model of bushing condition of transformers is proposed in this paper. Firstly, the hierarchical evaluation index system is constructed from the perspectives of qualitative and quantitative, which is based on experimental data and also considering the inspection tour program. Then, considering the shortages of single weighting in transformer condition assessment, this paper introduces a method to obtain the optimal weight. The subjective and objective factors are combined through solving the minimum deviation optimal function. Meanwhile, for the fuzziness and uncertainty of index information, the original reliability allocation of state variables are calculated and updated by adopting the fuzzy evaluation method. And then the modified evidence sources and combination rules are utilized to evaluate the bushing condition level. Finally, the results of case study show that this method is accurate and effective.