The invention discloses an electrostatic dust removal high-frequency high-voltage power supply system and a control method. The control method mainly comprises the steps that after the LCC resonance current and the secondary output voltage value of an electrostatic dust removal high-frequency high-voltage power supply pass a signal collection circuit, a conditioning circuit and an A/D switching circuit in sequence, a digital voltage signal is transmitted to a DSP control circuit; a DSP chip sends a PWM control signal to a digital logic unit and an IGBT driving circuit by combining the actual current and voltage values transmitted through a main circuit and comparing the actual current and voltage values with the preset values of the system; and the PWM control signal is used for controlling a full-bridge inverter finally by being processed and amplified. According to the control method related by the invention, the frequency converting control strategy and the phase-shifting control strategy are effectively combined, and disturbance of different stages of the system is subjected to hierarchical control through a double-loop-locked control structure, so that the dynamic characteristics of the system are improved, and the system has high adaptability to complex working conditions; and the frequency change of opening and closing is constricted, closing losses are effectively decreased, and the overall efficiency of the system is obviously improved.