A non-contact electromagnet loading method is designed based on problem of complicated structure, serious abrasion, and vibration existing in the contact loading of high speed motorized spindles. In this method, the load of practical cutting forces can be simulated by using dynamic electromagnetic force, and the dynamic non-contact loading is realized. The model of non-contact electromagnetic loading is established using electromagnetic theory, and the influencing factors of the electromagnetic force are analyzed. The key technology of electromagnetic loading is solved, and the integrated experiment is designed. Under the conditions of 9 000 r/min rotational speed and 40 mA excitation current, the dynamic loading experiment is carried out for a 170MD18Y16 grinding motorized spindle. The theoretical value is compared with the measured value of the dynamic electromagnetic force in various excitation currents and rotational speeds. The result indicates that changes are consistent, and errors between the theoretical value and measurement value of dynamic loading are small. The experimental results have verified the validity of the dynamic non-contact electromagnetic loading method, and loading under different conditions can be accomplished by changing the excitation current and rotational speed.