In Risk Priority Number(RPN) analysis based on Multi-Criteria Decision Making(MCDM), it is critically important to determine the weight of each expert in Failure Mode, Effects and Criticality Analysis(FMECA) of a product. For a widely used type of experts’ opinions, interval number information, subjective weights are determined by the index system of employment years, working experience and familiarity degree. Then based on the similarities of each two experts’ opinions, the method to calculate the objective weight is conducted. The multi-sources experts’ opinions are fused by an integrated weighting on the basis of above subjective and objective weights. At last, the effectiveness of proposed method is validated by a criticality analysis of the intrinsically safe power supply applied in mine.