The invention discloses a mine cooling system utilizing deep-well geothermal energy. The mine cooling system comprises an air treatment system, a geothermal energy recovery system and an underground cold water system. The air treatment system comprises a travelling trolley and an air treatment device arranged above the travelling trolley. The air treatment device comprises an air inlet located in the end of the air treatment device and an air outlet located in the tail of the air treatment device, and a first-stage air cooler, a first-stage rotary dehumidifier, a second-stage air cooler, a second-stage rotary dehumidifier, a third-stage air cooler, a water baffle and a fan are arranged between the air inlet and the air outlet. The invention further discloses a mine cooling method adopting the system. The air treatment system and the geothermal energy recovery system are arranged, the rotary dehumidifiers are arranged in the air treatment system, the geothermal energy is taken form a heat recovery filling body to be used for dehumidification regeneration of the rotary dehumidifiers, energy consumption of the mine cooling system is reduced, the downhole dehumidification difficult problem is solved, and the comfort of the mine working face is improved.