Good frequency response characteristics of high-voltage DC voltage divider is the basis of the reliable operation of the DC control and protection system. However, due to the lack of a portable high-voltage broadband test voltage source, the current DC voltage divider frequency response test can only be carried out during the delivery test, and generally only the power frequency voltage test is carried out, the actual on-site transient characteristics of the DC voltage divider cannot be effectively acquired in the field. Based on the high-voltage power amplifier and arbitrary waveform signal generator, this paper proposes a portable high-voltage broadband power supply, and improves the ability of the high-voltage broadband power supply to drive capacitive loads through inductance compensation measures. It can generate test voltages with a frequency range of 50~3 000 Hz and amplitude of 10 kV for DC voltage dividers of different voltage levels, so as to meet the frequency response test requirements of various DC voltage dividers. The frequency response test power supply and method designed in the article are light and easy to use, which is helpful to promote the on-site DC voltage divider frequency response characteristic test.