In view of the demand for repetitive charging of compact high-power pulse drive source, the constant current charging technology based on LC full bridge series resonant principle is studied, and the key parameters of the power supply are designed according to the working mode of compact Marx pulse power source. A compact high-voltage power supply with positive and negative bipolar charging is developed, charging the equivalent load capacitance of 0.15 μF to ±45 kV within 20 ms, and the average charging power is greater than 15.5 kW. The power supply uses a single high-frequency high-voltage transformer to achieve positive and negative bipolar high voltage synchronous output; the integrated insulation packaging design of transformer, rectifier circuit, isolation protection circuit and voltage detection circuit is adopted, which not only reduces the volume of the device but also reduces the risk of high-voltage insulation; through the design of isolation protection and electromagnetic shielding, the interference and damage of the instantaneous high-voltage signal to the power control system during the discharge of the Marx generator are effectively solved.