The invention discloses a multifunctional flexible grounding device, which comprises a transformer, a voltage source inverter, a winding current detection unit, an amplifier, a PWM drive signal generation unit, a capacitance current detection unit and a neutral point voltage detection unit. The winding current detection unit is used for generating a current signal. The amplifier amplifies the current signal to obtain a reference signal. The voltage source inverter is used for generating a current or voltage which is in the same frequency as the reference signal and acts on the secondary side winding of the transformer. The neutral point is grounded through the arc suppression coil, and the capacitance current detection unit is used for detecting the current of the grounding capacitor and calculating the first amplification factor, and the primary side winding of the transformer is equivalent to the continuously adjustable inductance. When the neutral point is grounded through the smallresistor, the neutral point voltage detection unit detects the neutral point voltage and calculates the second amplification factor, and the primary side winding of the transformer is equivalent to acontinuously adjustable small resistor. By means of different control modes, the two neutral point grounding modes can be realized without adjusting devices.