Abstract: Objective To elaborate the possible relationship and mechanism between the intake of dietary fiber and prostate cancer risk, and provide evidence for the nutritional prevention of prostate cancer. Methods We review and research the domestic and foreign published literature about the relationship between dietary fiber and prostate cancer. Results The latest Meta analysis of case control study showed that dietary fiber can reduce the risk of prostate cancer, but the Meta analysis of cohort study showed that the intake of dietary fiber was not associated with the risk of prostate cancer. Effect of dietary fiber on prostate cancer may be involved in the change of SHBG, testosterone and estradiol levels, the improvement of insulin sensitivity, the decline of the activity of insulin like growth factor , the apoptosis in human prostate cancer cells and the inhibition of adhesion and migration of prostate cancer cells. Conclusions The mechanism of the effect of dietary fiber on prostate cancer needs to be further studied. The existing research can not completely support the theory that dietary fiber can reduce the risk of prostate cancer.