The invention provides a distributed photovoltaic power generation power control method based on a virtual power plant. The distributed photovoltaic power generation power control method comprises the steps of: applying an active power optimized dispatching method to a virtual power plant control center, performing optimized distribution on an active power dispatching command of the virtual power plant issued by a power grid regulation and control center, and issuing the active power dispatching command after optimized distribution to distributed photovoltaic power generation units in the virtual power plant; and issuing node voltage reference values to the distributed photovoltaic power generation units in the virtual power plant by the virtual power plant according to the node voltage reference values issued by the power grid regulation and control center, wherein each distributed photovoltaic power generation unit automatically sets a sagging slope for carrying out reactive/voltage control according to the voltage reference value and a reactive power adjustable range thereof. The distributed photovoltaic power generation power control method provided by the invention realizes information management of distributed photovoltaic power generation, reduces the light discarding cost of the whole virtual power plant, and improves the operation efficiency; moreover, the distributed photovoltaic power generation power control method realizes the self-adaptive control of distributed photovoltaic power generation on grid-connected point voltage, reduces the influence of distributed photovoltaic power generation on power grid voltage, and ensures the normal operation of the power grid.