Abstract: This paper mainly considers the constraints of the peaking trend of the power grid,focus on the wind-photovoltaic-fire UHVDC external dispatching schedule to fully explore the complementary effect of the new energy DC delivery on the peaking capacity of the receiving power grid. First of all,the advantages of wind power,photovoltaic output and wind-light-fire bundling combined delivery are analyzed,then a scheduling model is established by both considering the maximum consumption of new energy and the improvement of the peaking margin of the receiving power grid. In the example,the CPLEX software is used to optimize the operation mode of DC external transmission. Results show that compared with the traditional fixed-power“linear”DC external transmission mode,the“multi-segment line”operation mode can effectively increase the new energy utilization rate and decrease the unfavorable peaking rate and source-charge disturbance rate of the power grid,which then contributes to improve the peaking margin of the receiving power grid.