To satisfy the sensorless vector control performance for PMSM, a sensorless control method based on CDKF algorithm is presented. It calculates the speed and magnet angle displacement based on parameter estimation method based on the voltage and current signals of the PMSM, then the speed and magnet angle displacement of vector control system are obtained. The simulation data demonstrate that the proposed method has high estimation precision and improves the computation efficiency effectively, and it meets the requirement of PMSM.