Abstract: Objective Combined with three-dimensional CT analysis of preoperative parameters of total hip replacement, through computer simulation of preoperative prosthesis placement position and model, to evaluate the guiding role of this technology in total hip replacement. Methods Patients who underwent primary total hip replacement in our department from August 2018 to June 2021 were selected. The study was divided into the observation group (30 cases) and the conventional control group (30 cases). The abduction angle, anteversion angle and rotation center distance were statistically analyzed according to the healthy side before the operation, and the position and model of the prosthesis were simulated by the computer before the operation. After the operation, the unequal length and functional score of both lower limbs were measured. Results The preoperative unequal length of the observation group was significantly better than that of the control group (P < 0.05). In the observation group, 24 cases were excellent, 4 cases were good, and the excellent and good rate was 93.33%; In the control group, 19 cases were excellent, 4 cases were good, and the excellent and good rate was 76.67%. There was significant difference in Harris functional score between the two groups at 3 months after operation (x2 = 7.31, P < 0.05). Conclusion Combined with the parameters of the healthy side hip joint, it is helpful to determine the position of the abduction, anteversion and rotation center of the prosthesis required by the computer-assisted total hip surgery. It has certain guiding significance to accurately determine the prosthesis model in the total hip replacement surgery.