The invention discloses a supercritical air energy storage/release system with a novel process. The off-peak (low price) electricity of the power station is adopted by the system to compress the air to a supercritical state (simultaneously store the heat of compression), an expansion machine is utilized to cool the air, simultaneously the work of expansion is recycled to drive a first-stage compressor to improve the system efficiency, and the stored cold energy is utilized to cool, liquefy and store (store the energy) the supercritical air; at a peak of electricity consumption, the liquid air is compressed and absorbs heat to be supercritical (simultaneously recycles the cold energy), further after absorbing the compression heat or the other industrial exhaust heat, the solar energy central heating and the like, the liquid air drives the generator to generate electricity (release energy) through a turbine. The supercritical air energy storage system disclosed by the invention has the advantages of having high energy density and high efficiency, being free from limitation of the energy storage period and the geography condition, being suitable for a variety of power stations (including regenerative energy power stations such as wind energy), being environment-friendly, being capable of recycling the middle-low temperature (heat value) waste heat, and the like.