An air purification system comprises an air purification device and a body temperature detection device, wherein the air purification device comprises a heat pump device, a water collection device, a controller and a casing; the heat pump device comprises a compressor, an evaporator, a first radiator, a second radiator, a solenoid valve, a check valve, an expansion valve and a fan, surfaces of the evaporator and the radiators are coated with nano-titanium dioxide coatings, the fan, the evaporator, the first radiator and the second radiator are arranged between an air exhaust port and an air inlet, a water collecting tank is located between the evaporator and the first radiator, and the second radiator is located between the fan and the evaporator. During work, an ultraviolet lamp tube is turned on, nano-titanium dioxide coating the surfaces of the radiators, the evaporator and the water collecting tank plays a catalytic role, harmful substances such as formaldehyde and the like in the air are removed, various harmful bacteria are killed, the air is purified, meanwhile, the radiators and the evaporator perform repeated dehumidification, the dehumidified air can be selectively heated or refrigerated.