In view of the fact that present evaluation methods such as AHP(the analytic hierarchy process) are vulnerable to the impact of subjective views and that fuzzy comprehensive evaluation''s membership selection tends to be subjective and arbitrary, a evaluation method based on particle filter algorithm is proposed. This method, based on the principle of particle filter, selects optimal value as a Gaussian random variable and uses particle filter iterative to strike a unit''s success probability density under a indicator.This method resolves the problem that other methods cannot resolve, the unability accurately and objectively reflect all tenders'' real gap under various indicators.This method makes evaluation get improvement in rationality and fairness. The effectiveness of the algorithm is shown by one bidding case’, whose computing and analysing indicates that the algorithm can be extended to other similar problems in the evaluation as well.