Objective To observe the changes of mechanical pain thresholds and autophagy related proteins microtubule-associated protein 1 light chain 3 (LC3) and sequestosome 1 (SQSTM1 also known as p62) expression levels in the C57BL/6 mouse models of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), and provide animal experimental evidence for CP/CPPS pain and autophagy study. Methods 36 male C57BL/6 mice were randomly divided into three groups:the model group, control group and naïve group. The CP/CPPS model was established by subcutaneous injection in the lower abdomen region with suspension liquid, containing protein extract of male SD rat prostate gland and complete Freund adjuvant. At 1month and 6 months after modeling, the mice were sacrificed and prostate tissues were harvested for histological examination using HE staining. Mechanical tactile hyperalgesia was measured with von Frey filaments. The autophagy-related proteins LC3 and p62 expression levels were detected by immunohistochemistry, respectively. The average IOD was measured by Image Pro Plus 6.0, and the statistical analysis was performed with GraphPad Prism 5 software. Results The histopathology showed the appearance of chronic prostatitis in the model group, representing hyperplasia and lymphocytic infiltration to a different degree and lasted for 6 months after modeling. Moreover, prostate intraepithelial neoplasia (PIN) appeared in the model group at 6 months after modeling, characterized by the disappearence of basement membrane and obvious nuclear abnormality, while the control and naïve groups showed normal histology during the 1-6 months. Compared with the control and naïve groups, the mechanical pain threshold in the model group was significantly decreased along with the time from (0.353±0.154) g at 0 week to (0.008±0.00) g at 22 weeks (P<0.05). The average IOD of LC3 and p62 expression in the model group was significantly increased with timing from[(2.767±0.464)%, (2.872±1.642)%] at 1month to[(13.501±1.900)%, (9.07±0.49)%] at 6 month, P<0.05. Conclusions A CP/CPPS model is successfully established in C57BL/6 mice. For the model group, the mechanical pain threshold is decreased and autophagy levels are increased gradually with time. These phenomena show that chronic inflammation microenvironment may promote pain and autophagy activity in the prostate, which is closely related with the occurrence and development of prostatic intraepithelial neoplasia.