Objective To explore the value of prostate biopsy guided by transrectal ultrasound combined with MRI compartmental localization in the diagnosis of prostate cancer. Methods Fifty patients with elevated prostate specific antigen levels were recruited in this study. All the patients underwent MRI scan before biopsy and the prostate was divided into 12 compartments accordingly. The direction and region of the division were consistent with the ultrasound. Systematic 12-samples needle biopsy was performed and additional biopsy was done for the suspected compartments. According to histopathology, the positive detection rates of systematic 12-samples needle biopsy and systematic biopsy combined with added punctures of suspected compartments were analyzed and compared. Results Prostate cancer detection rate of systematic biopsy combined with punctures of suspected compartment was significantly higher than that of systematic 12-samples needle biopsy (42.0% vs 36.0%, P<0.05). Systematic biopsy combined with punctures of suspected compartment caused hematuria in 5 cases, bloody stools in 13 cases, and fever in one, and there were no other complications. Conclusion Transrectal ultrasound combined with MRI compartmental localization can improve the outcome of prostate biopsy, benefiting the early diagnosis of prostate cancer.