The invention discloses a virtual synchronous machine low-voltage ride-through control strategy for rapid reactive power support, and provides an improved virtual synchronous machine control structureon the basis of conventional virtual synchronous machine control, and the structure can shield the reactive power-voltage sag characteristics and power errors of a virtual synchronous machine when the voltage of a power grid drops symmetrically, and reduces negative effects caused by power grid voltage drop due to voltage drop. Meanwhile, the invention provides a novel current reference value calculation method which can inhibit overcurrent and rapidly provide reactive power support for a power grid during low voltage ride-through. According to the invention, the method does not need a mode switching algorithm, the current impact caused by power grid voltage drop can be restrained, and the reactive power support can be rapidly provided for the power grid. Meanwhile, the active power and reactive power can be flexibly distributed according to power grid requirements, and the capacity of the grid-connected inverter is fully utilized.