To compare the clinical efficacy of arthroscopic outside-in suturing and all-inside suturing in the treatment of discoid lateral meniscus (DLM) injury, and to analyze the influencing factors for clinical efficacy. We retrospectively selected 30 patients with DLM injury who received arthroscopic all-inside suturing at Wuzhou Workers' Hospital from January 2020 to December 2022 as the observation group. Another 30 patients who received arthroscopic outside-in suturing during the same period were enrolled as the control group. The surgical indicators, pre- and post-operative knee scores and proprioception difference of knee joint, postoperative complications and clinical efficacy were compared between the two groups. Factors affecting clinical efficacy of patients with DLM injury were identified using Logistic regression analysis. Significant differences were observed in operation time, hospital stay, blood loss and clinical efficacy between the two groups (all P<0.05); however, there was no significant difference in complications (P>0.05). The visual analog score (VAS) scores of both groups decreased over time at 1, 3, 5, 7, 15, and 30 days post-surgery, with the observation group scoring lower than the control group (all P<0.05). At 1, 3, and 6 months after the surgery, the international knee documentation committee (IKDC), Lysholm, and Tegner scores of both groups increased over time, with the observation group scoring higher than the control group (all P<0.05). Six months post-surgery, proprioception differences at 15°, 45°, and 75° of knee flexion were significantly decreased, with greater improvements observed in the observation group (P<0.05). Univariate analysis showed that operation time, IKDC and Lysholm scores at 6 months post-operation, postoperative complications, and suture method were factors influencing treatment outcomes in patients with DLM injury (all P<0.05). Multivariate Logistic regression analysis identified postoperative complications as an independent risk factor for poor treatment outcome in patients with DLM injury (P<0.05). Arthroscopic all-inside suturing for DLM injury offers significant clinical benefits, including shorter operation time and hospital stay, less blood loss, and improved knee joint function with fewer complications. Prolonged operation time, low IKDC and Lysholm scores at 6 months post-operation, postoperative complications and outside-in suturing technique are associated with poorer treatment outcomes in patients with DLM injury.