Objective The functional relation between the correction angle and orthopedic force of scoliosis can be derived based on the force principle of scoliosis correction. The position and size of the orthopedic force with the best effect of spinal correction can be calculated to provide a theoretical calculation method for the application of orthopedic forces on scoliosis. Methods The coordinates of the scoliosis central axis were collected based on the computed tomography (CT) data of scoliosis. The spline curve of scoliosis was fitted using the MATLAB software. The scoliosis constitutive polynomial was obtained, and then, the scoliosis Cobb angle was calculated by programming. Based on the clinical medicine and experimental data of spinal biomechanics, a curved beam model was used for the correction calculation and analysis of scoliosis. Results The function relation between the orthopedic force and angle at any positions was derived at different orthopedic forces. The comprehensive elastic modulus of the spine was 0.29 MPa, as calculated by the function relation. Conclusions The calculation and analysis provided a reliable theoretical basis for the relationship between the loading position, size, and restoration angle of the orthopedic forces during scoliosis correction. For patients with different types of scoliosis, the function relation between the orthopedic angle and orthopedic force could be optimized to obtain the optimal orthopedic force and loading position.