The invention discloses a photovoltaic virtual synchrony control method of an inverter based on master-slave control. In the method, a photovoltaic inverter of a photovoltaic power station is set on the master-slave control mode; the master inverter executes a maximum power tracking control method; a slave inverter executes a photovoltaic virtual synchrony control method; and, the power and the voltage when the master inverter acquires the maximum power point are sent to the slave inverter through communication, so that the slave inverter adjusts the step size of tracking and the parameter offrequency modulation. The method provided by the invention improves the prior photovoltaic virtual synchrony control method, so that the slave inverter is always in the state of frequency modulation;and thus, the frequency of the power grid can be better adjusted.