Aim: To evaluate the effects of treating tibia avulsion fracture of the posterior cruciate ligament (PCL) by internal fixation with an adjustable double loop plate under the arthroscopic. Methods: Patients with a tibia avulsion fracture of the PCL were identified and were divided into two groups. X-ray, CT, and magnetic resonance imaging (MRI) were used to evaluate the injury and the fixation of the knee. The results of the range of motion (ROM), Lysholm score, International Knee Documentation Committee (IKDC) score, KT-10 0 0, and other clinical parameters were checked and recorded, and compared through the study. Results: A total of 26 patients were identified in this study according to the inclusion and exclusion criteria. The initial fixation was achieved the fracture fragments were well fixed in all patients and the fracture healed at 3 months postoperatively. The demographics and baseline characteristics showed no differences. There were no differences between the experimental group and the control group in IKDC score (54.1 +/- 6.2 vs. 53.2 +/- 7.1, P = 0.812), Lysholm score (37.5 +/- 4.1 vs. 36.8 +/- 2.5, P = 0.636), KT-10 0 0 score (9.8 +/- 0.6 mm vs. 9.6 +/- 0.4 mm, P = 0.401), and ROM (30 +/- 4.5 degrees vs. 31 +/- 3.7 degrees, P = 0.723) before the surgery. Compared with the preoperative results, in the experimental group, the postoperative ROM (133.5 +/- 6.3 degrees, P < 0.001), Lysholm scores (84.3 +/- 5.2, P = 0.001), and IKDC scores (4.5 +/- 5.1, P = 0.001) increased, and the postoperative KT-10 0 0 scores (1.6 +/- 0.4, P = 0.001) declined, there was a significant difference. Accordingly, in the control group, the postoperative ROM (131 +/- 4.2 degrees, P < 0.001), Lysholm scores (81.5 +/- 3.2, P = 0.001), and IKDC scores (83.6 +/- 3.7, P = 0.001) increased, and the KT-10 0 0 scores (1.7 +/- 0.5, P = 0.001) decreased, with a significant difference. The postoperative outcomes, ROM, Lysholm scores, IKDC scores, and KT-10 0 0 scores showed no significant differences between the two groups (P > 0.799). Conclusions: Compared with the conventional method, arthroscopic internal fixation with an adjustable double loop shows promise but requires further study.