Objective To evaluate the positional relationship between protective channel and sural nerve while treating acute Achilles tendon rupture with channel assisted minimally invasive repair (CAMIR) technique based on anatomical observations of cadaver specimens. Methods Twelve adult cadaveric lower limb specimens (6 left, 6 right) were utilized. A CAMIR device was implanted at a distance of 4 cm from the proximal end of the specimen to the Achilles tendon insertion. The skin was incised along the tendon’s medial side, the sural nerve was dissected, and the positional relationship with the protective channel was observed. The distance from the sural nerve-Achilles tendon intersection to the calcaneal insertion, the vertical distance between protective channel and the calcaneal insertion, and the horizontal distance between the sural nerve and protective channel were measured by using vernier caliper. Results Anatomical examination demonstrated a variable positional relationship between the sural nerve and protective channel, with the sural nerve positioned above (8 specimens) or below (4 specimens) the protective channel. The distance from the sural nerve-Achilles tendon intersection to the calcaneal insertion was (105.67±14.94) mm, the vertical distance between protective channel and the calcaneal insertion was (93.20±9.57) mm, and the horizontal distance between the sural nerve and protective channel was (0.31±0.14) mm. Conclusion The use of CAMIR technique for the treatment of acute Achilles tendon rupture can effectively avoid iatrogenic injury to the sural nerve.