To solve the problems of slow regulative speed and long adjustment time by using peer-to-peer power regulation mode in high-capacity photovoltaic power station with numbers of inverters, a power conditioner system based on multicast is proposed, which sends the remote adjustment command to the inverters in the station at once by using UDP multicast to improve the regulative speed. The structure, control method and control strategy of the power conditioner system is introduced. It makes use of the reactive power of the inverters instead of the SVG in the voltage/reactive power control, which reduces the cost of large-scale photovoltaic power station effectively. The system has been successfully used in Jinchang Zhenxin 100 MWp photovoltaic power station in Gansu province and the method proposed is validated.