The invention discloses an energy complementation self power supply system, which comprises a solar energy power generation device, a wind energy power generation device, a methanol-water reforming hydrogen production power generation module, an AC DC power conversion device, an electrolytic hydrogen production device, a first methanol synthesis device, a methanol-water storage and conveying device and a load, wherein the solar energy power generation device and the wind energy power generation device provide power for the load and the electrolytic hydrogen production device; the electrolytic hydrogen production device is used for electrolyzing water for hydrogen production, the produced hydrogen is fed to the first methanol synthesis device for synthesizing methanol, in the condition of not sufficient solar energy and wind energy, the synthesized methanol is conveyed to the methanol-water reforming hydrogen production power generation module for hydrogen production and power generation, and power is provided for the load; and the methanol-water reforming hydrogen production power generation module comprises a reformer and a fuel cell, methanol and water are subjected to a reforming hydrogen production reaction in the reformer, the produced hydrogen is fed to the fuel cell, and in the fuel cell, the hydrogen and oxygen in the air are subjected to an electrochemical reaction, and power output is generated. Multiple energies generate power in a complementary mode, power supply continuity is good, and control is easy.