The invention discloses a high-power voltage-controlled negative resistance for a resonant circuit, comprises a connected AC controlled current source and a control circuit, the AC controlled currentsource and the control circuit are respectively connected with the resonant circuit, the control circuit comprises a switch driving module which is connected in turn, zero-crossing comparison module,a phase compensation module and a voltage sampling module, the voltage sampling module samples the input voltage of the resonant circuit, A phase compensation module and a zero-crossing comparison module convert the phase compensation module and the zero-crossing comparison module into a square wave which is completely inverted from the input voltage, and a driving signal of the switching device is generated to an AC controlled current source which generates a fundamental current between a positive output terminal and a negative output terminal according to the driving signal through a switching driving module. The invention can realize different power levels, has the characteristics of flexible working characteristics and on-line adjustable, and provides a reference for the practical application of the negative resistor in various power occasions.