Magnetic components are important parts of power converters. The accurate core loss measurement is very important for the optimization of magnetic components. To improve the measurement accuracy of the traditional dual-winding AC power method for core loss measurement with high-frequency excitation, the measurement principle and error source of the inductor voltage compensation AC power method are analyzed in detail. Based on the error problem that the core loss of magnetic components with high impedance angle is measured with the inductor voltage compensated AC power method under incomplete compensation, the inductor voltage partially compensated AC power method is proposed to accurately measure the core loss under arbitrary waveform excitation in this article. Finally, the measurement platform is established under the condition of incomplete compensation. The maximum relative error of this method for core loss measurement of the powder core with 50 kHz sine wave excitation is 13. 54% , and the maximum relative error of core loss measurement of the powder core with 50 kHz rectangular wave excitation is 9. 8% . Experimental results show that the core loss of magnetic powder core under sine wave and square wave excitation can be accurately measured by the proposed method.