The invention relates to motors and the power electronic technology, and particularly relates to a VVSG (Voltage-sourced Virtual Synchronous Generator) technique-based large synchronous phase modifierstarting method. The VVSG technique-based large synchronous phase modifier starting method comprises the following steps: 1, introducing a VVSG control strategy, setting virtual inertia, respectivelysetting a curve of the angular frequency instruction value and the voltage instruction value; 2, introducing a closed-loop control of the rotor speed to an excitation regulator, and regulating the speed by regulating the exciting current. The method avoids the various defects of the SFC (Static Frequency Convertor) of the existing large synchronous motor starting device like the hidden danger ofphase change failure, poor system adaptability, poor vector control accuracy, low grid connection reliability of the coasting operation grid connection mode; the frequency conversion part is equivalent to a voltage source virtual synchronous generator, the large-capacity synchronous generator is equivalently dragged to the synchronous phase modifier having a relatively small capacity to start, therotor speed of the synchronous phase modifier is guaranteed to stably increase until the rated speed, and the method has a better development potential and promotion space.