A　novel　quasi-resonant　active　disturbance　rejection　control　(QRADRC)　method　is　proposed　for　suppressing　current　harmonics　and　improving　system　robustness　of　permanent　magnet　synchronous　motor　(PMSM).　The　structure　of　the　traditional　linear　extended　state　observer　(ESO)　is　improved　by　paralleling　a　quasi-resonant　link　in　the　disturbance　estimation　loop.　Therefore,　the　novel　quasi-resonant　extended　state　observer　(QRESO)　is　constructed　and　applied　to　the　linear　active　disturbance　rejection　current　loop.　The　basic　ESO　in　the　novel　QRESO　is　used　to　estimate　the　DC　disturbance,　and　the　quasi-resonant　link　is　introduced　to　estimate　the　AC　disturbance,　so　that　the　novel　QRADRC　could　not　only　suppress　the　DC　disturbance　caused　by　the　motor　parameter　perturbation　effectively,　but　also　greatly　improve　the　ability　of　suppressing　the　AC　disturbance　caused　by　the　current　harmonics.　In　this　paper,　the　harmonic　suppression　ability　and　anti-disturbance　ability　of　the　novel　QRADRC　are　analyzed　theoretically　and　verified　by　the　simulation　and　experiment.　The　results　show　that,　compared　with　the　traditional　proportional　integration　(PI),　proportional　integration　resonance　(PIR)　and　active　disturbance　rejection　control　(ADRC)　methods,　the　novel　QRADRC　method　can　significantly　reduce　the　5th　and　7th　harmonics　of　phase　current　and　the　6th　harmonics　of　torque　current,　and　has　stronger　robustness　for　time-varying　motor　parameters.　©2023　Chin.Soc.for　Elec.Eng.