When measuring the losses of magnetic component excited at frequencies up to 100 MHz using electrical measurement methods, the high-frequency parasitic parameters can lead to significant measurement errors. The calorimetric method is utilized to measure the losses of magnetic component under ultra-high-frequency excitation in this paper. The errors of the closed calorimetric method stem from the determination of specific heat capacity, heat dissipation, and heat from accessories. Typically, the calibration calorimetric method is employed to eliminate the measurement errors of the closed calorimetric method. Traditional calorimetric method uses direct current (DC) power as a standard to verify the power-temperature rise (P-ΔT) relationship. The errors of the DC power calibration calorimetric method arise from inconsistent environmental conditions between the calibration and measurement processes, particularly the difference between the DC and AC equivalent resistance of connecting wires, which causes measurement errors that increase with the excitation frequency. This paper proposes an alternating current (AC) power calibration calorimetry method for measuring the losses of magnetic components under ultra-high-frequency excitation. By using AC power as a standard to verify the P-ΔT relationship, and ensuring the same excitation frequency during both calibration and measurement, this method eliminates measurement errors caused by inconsistent of connecting wire losses. The remaining measurement errors in this approach mainly result from the influence of high-frequency parasitic parameters. Following a detailed analysis of the principles and error sources associated with the calibration-based calorimetric method, corresponding solutions are proposed. A measurement platform for magnetic component loss evaluation is constructed, and an upper computer measurement interface is developed to enable automated measurement. Finally, an air-core inductor with accurately measurable losses is used as the inductive device under test. Experimental results verify that the calibration calorimetric measurement platform can accurately measure the losses of magnetic components excited by sinusoidal waves within the frequency range of 100 MHz.