The invention discloses a comprehensive energy source management system for peak shifting power supplying and a method thereof. The comprehensive energy source management system for peak shifting power supplying comprises an air compressor (1), a power generator (2), an air precooling device (3), a primary level cooler (4), a secondary level cooler (5), a throttling valve (6), an air-liquid separator (7), a liquid state air storage tank (8), a liquid state air pressurizing pump (9), a nitrogen oxygen separator (10), a heating water tank (11), a high-pressure turbine (12), a low-pressure turbine (13), a power generating set (14), a nitrogen storage tank (15), a nitrogen exhaust pipe (16), a heat return pipeline (17) and a liquid oxygen pipe (18). The comprehensive energy source management system for peak shifting power supplying is characterized in that the whole system takes energy storage as a core, at the electricity using valley, energy generated by the power generator (2) is converted into liquid air to store, and is converted into a high-pressure gas by the heat exchanger in the electricity using peak, a turbine expansion machine is driven to generate electricity, and peak shifting power supplying is realized.