The invention discloses a plasma resonant power supply system based on adaptive power control. The system comprises mainly comprises a full bridge inverter circuit, a series and parallel resonant circuit, a filtering circuit, a transformer, a plasma load, a current sampling module, a voltage sampling module, a control system and a driving circuit. The invention provides an adaptive power control system, the control modes include a MODE1 mode and a MODE0 mode, and the two control modes can be switched freely according to a load state. In the MODE1 mode, a pulse signal frequency is constant, and a purpose of adjusting power is achieved through adjusting a pulse width. In the MODE0 mode, the pulse signal pulse width is constant, and a purpose of adjusting the power is achieved through adjusting the pulse frequency. In addition, according to the series and parallel resonant circuit provided by the invention, a direct current component can be effectively prevented from entering into the transformer and the output voltage of the inverter is converted into resonant series current and parallel voltage, thus the switching loss of a power tube is reduced, and the efficiency of the system is improved.