Abstract: The paper proposes a "rectifier station-photovoltaic power station" transient overvoltage hierarchical control strategy. Firstly,the principle of transient overvoltage at the sending end of the high-proportion photovoltaic DC transmission system is analyzed,and a layered control model of transient overvoltage of "rectifier station-photovoltaic power station" is established. Then,combined with the joint calling method and the consistency algorithm,the control model is solved,and the transient overvoltage is suppressed through the optimization control of the rectifier station camera parameters and the reactive power back-off distribution control of the photovoltaic inverter. Finally,taking a high-proportion photovoltaic power grid in Northwest of our country as an example,an experimental simulation model of a DC transmission system with high-proportion photovoltaic access is established. The example analysis results show that the transient overvoltage hierarchical control strategy proposed in this paper massively enhances the regulation capability of the power system.