The invention discloses a novel virtual synchronous generator control method and system by considering dynamic characteristics of a photovoltaic power supply. The method comprises the steps as follows: the photovoltaic power supply is dynamically analyzed; a feasible stable operation region of the photovoltaic power supply is obtained; and a core control unit ensures that the photovoltaic power supply runs in the feasible stable operation region. According to the method and the system disclosed by the invention, the photovoltaic power supply is directly combined with a virtual synchronous generator, so that the disadvantage that a traditional method also needs an energy storage battery for cooperation is avoided. The dynamic characteristics of the photovoltaic power supply are fully considered by the method, so that the photovoltaic power supply constantly runs in the stable region; a control variable obtained by considering the dynamic characteristics of the photovoltaic power supply is applied to the virtual synchronous generator in a form of the additional core control unit; and good combination of the photovoltaic power supply and the virtual synchronous generator is achieved. According to the method, the characteristics of the photovoltaic power supply are fully considered; excellent performance of the virtual synchronous generator is developed; meanwhile, the grid connection cost of the photovoltaic power supply is saved; and development and popularization of photovoltaic power generation are facilitated.