[Objective] To explore the best lateral lying and turning angle to prevent deep pressure injury by constructing a three-dimensional finite element model of sacrococcygeal tissue and carrying out mechanical analysis. [Methods ] CT data of sacrococcygeal region of healthy ———————————————————————— 作者简介：田园，主管护师，硕士在读，研究方向：护理学，(电话) 15022064403，(电子邮箱) tianyuan20230114@126.com *通讯作者：王春梅，(电话) 18002178512，(电子邮箱)cmwang8543@126.com adult male volunteers in prone position were selected to construct three-dimensional finite element models containing skin, subcutaneous fat, muscle tissue, bone and support pad at 0°, 15°, 30°, and 45° side-lying turning angles. Boundary conditions and loads were set on the four models. To analyze the Von Mises stress, shear stress and distribution characteristics of pressure injury model of sacrococcygeal deep tissue. [ Results] The maximum Von Mises stress and shear stress were all at the bone-muscle interface under different lateral lying and turning angles. When the turning angle was changed from 0° to 30°, the maximum Von Mises stress decreased from 0.539Mpa to 0.335Mpa, and the maximum shear stress decreased from 0.155MPa to 0.062MPa. However, when the angle increased to 45°, the two stresses increased to 0.518MPa and 0.087MPa, respectively. [Conclusions] The minimum stress was found when the turning Angle was 30°. It is recommended to use a 30° turning angle to prevent deep tissue injury.