The accuracy of dynamic force applied on specimen by fatigue test equipment is not the same as that of static force, and this perplexes testers and calibrators for a long time. By establishing physical vibration models of fatigue testing equipment, it is concluded that the error of cyclic force is mainly caused by the inertia force of the vibration mass between machine sensor and sample, which are not at the same position. Correction models of inertia force influence on cyclic force amplitude are deduced. After the inertia force influence is corrected, the display force of a fatigue test equipment is consistent with the actual force on the sample at last. The cyclic force calibration system with inertia force correction is established using the acceleration method and the stiffness/displacement method. By way of comparison test and data analysis, both the difference between two correction methods (acceleration method, stiffness/displacement method) and the difference between two calibration methods (sensor method, calibration bar method) are less than 1%. The validity of the inertial force correction model is verified.