The invention discloses a direct current power grid voltage optimization control method for multi-end-comprising photovoltaic power generation system, and relates to the technical field of a control method for the direct current power grid voltage of a photovoltaic power generation system. The method comprises the following steps of starting voltage optimization control when the direct current power grid generates voltage deviation through droop control, changing intercept of a direct current voltage-active power droop characteristic curve of a networking current converter G-VSC, enabling the G-VSC to perform charging-discharging to a direct current network side capacitor through additionally issuing or absorbing power, and enabling the direct current voltage to be recovered and maintained at a rated value. By virtue of voltage optimization control in the method, the voltage which deviates due to droop control can return to the rated value, so that the purpose of direct current voltage no-deviation regulation can be achieved, and the operation of the photovoltaic power generation system can be more stable.