The invention discloses a DC contact line power based stepped power generation plan optimization method. By adopting the DC contact line power as a resource to be optimized and adjusted, various characteristic requirements of DC power adjustment are met; the characteristic that a DC contact line can be flexibly adjusted is fully developed; multiple cross-regional DC transmission channels can be considered; the actual operation requirements of the DC contact line are met; the complementarity of system loads between a sending-end power grid and a receiving-end power grid and the new energy acceptable capacity are considered at the same time; the potential of the DC contact line in promotion of cross-regional new energy acceptable is further exploited; the receiving-end power grid is effectively supported at a load peak and the wind/solar new energy consumption power of the sending-end power grid is improved; consumption of the new energy within a larger space range is effectively promoted; and the overall benefits of the power grids are improved.