Cross-seasonal underground energy storage system and method based on solar spectrum modulation

The invention discloses a cross-seasonal underground energy storage system and method based on solar spectrum modulation. The system comprises a solar spectrum modulation section, a light path conduction section and a water circulation section, the solar spectrum modulation section comprises a solar total absorber and a selective emitter which are connected into a whole, and a TiN film covers the top of the total absorber; the optical path conduction section comprises a plurality of sections of optical fiber type conduction walls and an optical glass sleeve, the optical fiber type conduction walls are made of reflective SiO2 glass and can carry out lossless total reflection on light according to the optical fiber principle, and the plurality of sections of optical fiber type conduction walls are nested in the optical glass sleeve at intervals in a close fit mode; a light path is transmitted and reflected by the optical fiber type conduction wall and is emitted into soil from the middle of the adjacent section