A double-winding permanent magnet synchronous motor (PMSM), which has two groups of three-phase windings on its one stator, has a coupling effect between the windings. This paper explains the deterioration of the current control performance of a double-winding PMSM by using a voltage equation of the motor. The proposed coupling cancellation control method improves as demonstrated by the results of simulations and experiments. A design method for the coupling cancelling control with a Bode diagram is also discussed.