Abstract: The dead time in the inverter will aggravate stator current distortions and increase torque ripples, which may cause undesirable vibrations and additional power losses. To address these issues, this paper proposes a dead time on-line compensation method based on a high-order extended state observer (HO-ESO). In this method, the effects of dead time are firstly analyzed, and the d- and q-axis error voltage equations caused by the dead time are accordingly derived. Then, the conventional dead time effect compensation method based on the second-order ESO is introduced and analyzed. It is revealed from the analysis results that this method fails to accurately estimate error voltage, leading to a degraded performance of dead time compensation. Afterward, a HO-ESO is designed to estimate the error voltage, and the estimated error voltage is effectively compensated. Finally, extensive simulations and experimental tests are used to verify the performance of the proposed dead time compensation method, and they are compared with the conventional dead time compensation method based on a second-order ESO. The test results point out that the proposed method has a better performance, compared to the second-order ESO-based method. In addition, the proposed dead time compensation method does not require the detection of current polarity, which enjoys the benefits of easy implementation.