There is a problem of interior permanent magnet synchronous motor (IPMSM) control performance degradation due to various uncertainties such as internal parameter changes and external disturbances. Thus a model-free super-twisting fast terminal sliding mode control method is proposed. First, a new ultra-local model is established for IPMSM considering its uncertainty. The model-free super-twisting fast terminal sliding mode controller is designed by combining the super-twisting algorithm with the fast terminal switching function to ensure that the system state can reach the steady state in a finite time and effectively reduce chattering. Second, an extended sliding mode disturbance observer is designed to estimate the unknown part of the ultra-local model accurately, and feedforward compensation is performed to the designed controller. This further improves the anti-interference ability and system tracking performance. Finally, by comparing with PI control and conventional model-free sliding mode control methods, the simulation and experimental results verify that the presented method has faster convergence and stronger robustness.