[Objective] To observe the effects of anterior cruciate ligament (ACL) retained stump anatomical reconstruction combined with platelle-rich plasma (PRP) intra-articular injection on patellofemoral joint degeneration. [Methods] From June 2016 to June 2017, 50 patients with ACL injury who met the inclusion criteria were divided into the observation group and the control group according to the random number table, 25 cases in each group. The observation group was treated with ACL retained stump anatomical reconstruction and intra-articular injection of PRP. The control group was only treated with ACL retained stump anatomical reconstruction, and continued follow-up after operation. Kujalar score, Tegner activity score, VAS pain score and Rose cartilage injury classification were used to evaluate the changes of patellofemoral joint. [Results] 22 cases in the observation group and 21 cases in the control group were followed up for more than 2 years. Two years after the operation, there were statistically significant differences in the Kujalar score, Tegner activity score and VAS pain score between the two groups compared with those before the operation (P<0.05). Compared between the two groups, Kujalar score and Tegner activity score in the observation group were higher than that in the control group, with statistically significant differences (P<0.05), and VAS pain score in the observation group was lower than that in the control group, with statistically significant differences (P<0.05). The grade of cartilage injury of patellofemoral joint in the two groups was upgraded to different degrees compared with that before operation, mainly increased in grade II, and the difference was statistically significant (P<0.05). The grade of Rose cartilage injury in the observation group was significantly lower than that in the control group (P=0.002). [conclusion] ACL retained stump anatomical reconstruction combined with intra-articular injection of PRP can effectively reduce patellofemoral joint pain after reconstruction and delay the degenerative process of patellofemoral joint.