Objective To verify the effect of the new anatomical marking localization method (shoulder-to-shoulder) in restoring limb length during hip joint replacement. Methods Anatomical observation of the "shoulder" of the femur in 4 cadavers and total hip replacement were performed. The postoperative anteroposterior radiographs of the pelvis were used to measure the limb length, the acromion distance, the inter-osteal distance, the longitudinal and horizontal offset of the femoral head rotation center, acetabular abduction angle and anterior tilt angle were compared with the Artificial Intelligence-assisted Planning System (AIHIP). Results The "shoulder" of the proximal femur was the lower margin of the external muscle tendon end of the closed hole, that is, the lowest point of the rotor cavity. The postoperative imaging and AIHIP planned false limb limb lengths of the same side were 35.24±3.52 mm and 33.75±3.86 mm, respectively. The difference was 1.49±1.17 mm (90%CI: -0.38, 3.36), and the same length was established (Pdifference≤-5 = 0.0008, Pdifference≥5 = 0.0047); the acromion distance was 15.49±1.50 mm and 17.00±2.16 mm, respectively, the difference was -1.51±1.48 mm (90%CI: -3.26, 0.24); the inter-osteal distance was 8.38±2.27 mm and 7.50±2.65 mm, respectively, the difference was 0.88±0.99 mm (90%CI: -0.29, 2.04); the longitudinal offset of the rotation center was 12.48±1.92 mm and 12.00±2.16 mm, respectively, the difference was 0.48±2.03 mm (90%CI: -1.91, 2.87), the difference was not statistically significant (P=0.135, 0.174, 0.667).The horizontal offset of the center of rotation was 34.8±5.9 mm and 32.8±6.4 mm, respectively, with a difference of 2.0±2.9 mm (90% CI: -10.52, 6.48), none of which was statistically significant (P=0.135, 0.174, 0.667, 0.660); the angle of acetabular adduction was 32.5±3.1° and 41.3±2.5°, respectively with a difference of 8.8±3.3° (90% CI: 4.87, 12.63); and acetabular anterior tilt angle of 25.3±9.4° and 18.8±2.5°, with a difference of -6.5±11° (90% CI: -15.94, 2.95), respectively, with statistically significant differences (P=0.005, 0.030). Conclusion Based on anatomical and experimental studies, the new anatomical marking localization method of "shoulder-to-shoulder" on the femur side can guide the accurate implantation of the prosthesis on the femur side during the operation and effectively restore limb length.