Abstract: Objective To investigate the diagnostic value of urinary exosomal circ_0040507 combined with prostate-specific antigen （PSA） for prostate cancer. Methods Digital droplet polymerase chain reaction （ddPCR） was employed to detect the expression level of circ_0040507 in the urinary exosomes of 35 patients with prostate cancer and 27 patients with benign prostatic hyperplasia. The pathological results of prostate biopsy were regarded as the gold standard. The receiver operating characteristic （ROC） curve was delineated to analyze the sensitivity and specificity of urinary exosomal circ_0040507, PSA and the combination of them for the diagnosis of prostate cancer. Results The expression level of urinary exosomal circ_0040507 in the BPH group was （3.25±2.45） copies/ml, significantly lower compared with （8.35±5.87） copies/ml in the prostate cancer group （P < 0.001）. The area under ROC for circ_0040507, PSA, and the combination was 0.767 （95%CI 0.649-0.896）, 0.782 （95%CI 0.668-0.896） and 0.851（95%CI 0.755-0.946）, respectively. Conclusion The determination of urinary exosomal circ_0040507 combined with PSA is a valuable biomarker for the diagnosis of prostate cancer.