Abstract: A theoretical model for calculating external load of inclined shaft in the cylindrical coordinate is established. Compared with vertical shaft, inclined shaft has two basic characteristics of complex load type and non-centrosymmetric load distribution. Load of inclined shaft into three categories: radial load, circumferential load, and axial shear load. Differing from vertical shaft that radial load uniformly distributes along the circumference, the radical and axial shear load of inclined shaft are on the Y axially symmetric and the circumferential load is on the Y axially anti-symmetric. All the three types of load achieve a minimum value in the two sides of shaft, the value of shear load is 0 and which of radial load is equal to the lateral pressure of corresponding depth vertical shaft. In the circumferential direction angle 45°and 135°, all the three types of load are not equal to zero, the circumferential shear load achieve a maximum value, which are the key control points of design and calculation. Differing from vertical shaft“vertical additional stress”distribution, inclined shaft axial shear load above and below the horizontal axis plane is reverse distribution, the load direction above the horizontal axis plane is down and below the plane is up, the maximum of the load is 7 times than the “vertical additional stress”of vertical shaft. In the normal project of which inclined angle ranges from 0°to 30°，the external load increased approximately linearly with the inclined angle. The outer diameter b of inclined shaft has a similar effect on load, which can be ignored. Research results provide the basis for the analysis of inclined shaft stress distribution, design theory and calculation methods.