User comment is an important criterion for the approach of web service recommendation. But estimating the credibility of user comment is always a big challenge. This paper proposes a novel method to calculate the trust degree of the user evaluation. In the proposed method, the trust degree of the user evaluation is estimated with difference value derived by comparing the user satisfaction degree with user comment. Then the paper proposes an approach of web service recommendation based on the credible user evaluation. In the final, we present an experiment to prove the new approach which is accurate and effective can avoid the influence of false user comment.