Objective Common peroneal nerve (CPN) injury is a frequently encountered lower extremity injury. Furthermore, several previous studies have demonstrated that patients who underwent direct suturing of the CPN following rupture experienced unfavorable postoperative prognoses. Therefore, we aimed to present a novel modified surgical approach for CPN rupture and assess the effectiveness of this technique in restoring lower limb functionality. Methods In this retrospective observational study, we included patients with CPN rupture who underwent one‐stage neurorrhaphy and posterior transposition combined with nerve wrapping using a gastrocnemius fascial flap for CPN rupture between January 2016 and December 2020. Lower limb function was evaluated using the lower extremity functional scale (LEFS) and British Medical Research Council (BMRC) grading system. We also assessed the influence of age, sex, duration of symptoms, mechanism of injury, and surgical modality on the postoperative recovery of lower extremity function using subgroup and regression analyses. Results Thirty‐seven patients (mean age = 35.76 ± 13.01 years) with at least 2 years of follow‐up were included in the final analysis. The LEFS scores significantly improved after surgery at the last follow‐up (p < 0.01). Moreover, 67.57% of the patients achieved good or excellent postoperative outcomes (BMRC: M3 or above). Results of the subgroup analysis and regression models suggested that patients who underwent direct suturing showed better recovery of lower extremity function than those who underwent nerve grafting. Conclusion One‐stage neurorrhaphy and posterior transposition combined with nerve wrapping using a gastrocnemius fascial flap exhibited encouraging outcomes in restoring lower‐limb function among patients with CPN rupture. This novel surgical technique is expected to be an effective method for treating CPN ruptures in the future. When the common peroneal nerve is injured, scar adhesions and nerve compression can occur at two physiological constriction points, namely the fibula head and the fibular tunnel. Wrapping this segment of the peroneal nerve with the gastrocnemius fascial flap and posteriorizing it can create a favorable environment for nerve regeneration and prevent scar compression.