The embodiment of the invention provides a cross-regional power delivery multi-energy complementary optimization method and device, and belongs to the field of power technology. The cross-regional power delivery multi-energy completement optimizing method comprises the following steps: calculating performance evaluation indexes at different moments according to wind power delivery power, photovoltaic delivery power and hydropower delivery power of a delivery end power grid at different moments, as well as wind power acceptable power, photovoltaic acceptable power and hydropower acceptable power of a receiving end power grid at different moments; and calculating the power-on start/stop manner of a thermal power generating unit according to the performance evaluation indexes at different moments. The power demand of the receiving end power grid is taken into consideration, and optimal scheduling of cross-regional wind power, hydropower, photovoltaic and thermal power is realized, so thatan optimization scheme is provided for the delivery consumption of cross-regional clean energy, and the power consumption cost of power grid enterprises is lowered.