A method for analyzing limit pretension force of an angular contact ball bearing under fixed-position pretension of a high-speed electric spindle belongs to the technical field of bearing pretension. According to the method, firstly, parameters including a bearing type, a working condition, maximum permissible stress of a material and the like are determined; secondly, based on a Hertz contact theory, the influences of pretension force, centrifugal force and gyroscopic torque of the bearing are considered, and a kinetic model of the angular contact ball bearing under the fixed-position pretension is established, wherein the kinetic model includes a contact region model of the angular contact ball bearing, a pretension model of the angular contact ball bearing in a static state of the spindle, and a pretension model of the angular contact ball bearing in a rotating state of the spindle; thirdly, a relation between the pretension force and maximum contact stress of a bearing rolling body and bearing inner and outer rings under the condition of rated speed is solved with a Newton method; and finally, the pretension force, i.e., the limit pretension force, of the bearing under the permissible stress of the material is analyzed out.