Objective To compare the clinical effects of reconstructive surgery and conservative treatment on posterior cruciate ligament (PCL) injury. Methods 30 patients with PCL injury of surgical treatment from January 2014 to January 2015 in Lanzhou Military General Hospital were selected as the observation group. 30 patients with PCL injury voluntarily accepted conservative treatment from January 2012 to January 2013 in our hospital were selected as the control group. After 6 months of treatment, 12 months 24 months followup, the efficacy was evaluated with Lysholm scores and IKDC. Results Lysholm scores and IKDC of the two groups before treatment were no significant difference (P＞0.05). 6 months, 12 months and 24 months after injury Lysholm scores and IKDC of the observation group were significantly higher than that of control group (P＜0.05). The excellent and good rate of observation group and control group were 96.67% and 73.33% (P＜0.05). The excellent rate of observation group and control group were 73.33% and 4667% (P＜0.05). The IKDC score of the two groups had no significant difference before treatment (P＞0.05). After injury, the Lysholm scores and IKDC of observation group 24 months after injury was significantly better than that of the control group (P＜0.05).Conclusion For PCL injuries, the effect of endoscopic reconstruction on knee joint function is remarkable.