Online comments are a basis for users to judge the quality of a product, and fake reviews seriously affect the purchase behavior of consumers. Existing fake review detection methods focus on the text and ignore the falseness of scores. Due to inaccurate and uncertain scoring, fake review detection does not work well. We propose a fake review detection method (EP-BFRD) using emotional polarity and trust function. The trust function is used to deal with the uncertainty and inaccuracy in a given reviewer's score, which are then combined with the similarity to other provided ratings to detect misleading, and to judge the consistency between the emotional polarity of the review text and  the score. A fake review is determined by both the processing results of the trust function and the consistency between the scores and text emotion. Experiments on a real database show that the proposed method is an effective solution to fake review detection problem.