Aiming at the problem of speed sensorless control of high speed permanent magnet synchronous motor (PMSM), a speed sensorless control strategy of PMSM based on discrete back electromotive force (EMF) estimation was presented. The discrete back EMF estimation was implemented with three design considerations. First, a discrete dq current observer was designed to eliminate the inductive crosscoupling effect in the backEMF estimation. Then, a delay compensation model was designed to compensate for the voltage error caused by digitaltoanalog conversion. A more accurate discrete model to overcome the deviation between the estimated back EMF and the actual back EMF caused by the digital implementation. Finally, the drive tests of high speed PMSM were carried out. The test results verified the performance of the proposed high speed sensorless speed control scheme of PMSM.