Abstract: This paper proposes a resonance boosting and voltage double circuit for high voltage power supply, which consists of an LC resonant circuit and a rectifier. The working mode and the steady-state output characteristics of the circuit are analyzed. The mathematical models of the circuit are established in normalized forms to describe the output voltage and output current in steady-state, to express the characteristics of the circuit under short-circuit and open-circuit conditions, to give the expressions of the output voltage ripple, the output voltage drop and the electrical stress on the devices. The circuit quality factor, the normalized frequency and the capacitance ratio are defined, and their effects on the output characteristics of the circuit are analyzed. Simulation analyses and experimental researches have been performed for the circuit, and the simulation results are in good agreements with the experimental results, which verifies the correctness of the mathematical model. In contrast to the traditional C-W circuit, the proposed circuit has the advantages of stable voltage output, small voltage drop, good performance under short circuit condition, and fast response, which is suitable for high voltage and low current applications.