It is difficult to measure the magnetisation characteristics of magnetic powder cores with small loss angle and high saturation flux density. Here, a new pulse measurement method is proposed, in which the capacitance with preset bias voltage applies pulse excitation voltage to the measured magnetic component through RLC oscillation discharge, and the air core inductor whose permeability is vacuum permeability is used as the standard magnetic component to eliminate the numerical differential error of the traditional pulse measurement method. Based on the detailed analysis of the measurement principle and error source of the new pulse measurement method, the measurement system is established. The impedance analyser method is used to verify that it can accurately measure the magnetisation characteristics of the magnetic powder core with small loss angle.