To achieve carbon neutrality, China has vigorously promoted the high-quality development of renewable energy. By 2024, the installed capacity of new energy such as wind and photovoltaic (PV) power has reached 1.4 billion kW, surpassing that of coal-fired power for the first time. This paper focuses on power transmission curve optimization for large-scale wind-solar-storage integrated multi-energy complementary bases. Firstly, based on local new energy resources, the regulating resources such as pumped storage hydropower and solar thermal stations are configured. With the goal of maximizing the power generation benefits, matching the power transmission curve, multi-energy complementary optimal operation is simulated. Secondly, based on the output of multi-energy complementary bases, considering the capacity constraints of transmission corridors, annual transmission guarantee rate and abandonment rate of new energy, a probabilistic three-stage power transmission curve is proposed. A case study of renewable energy (RE) Base in DGB (Deserts, Gobi & Barren lands) region is conducted to validate the approach. This research provides valuable references for formulating power transmission curves for multi-energy complementary bases, and facilitates the commercial operation for DGB RE bases.