Cold point cooling device, injection water system and cold point cooling method

The invention provides a cold point cooling device, an injection water system and a cold point cooling method. The cold point cooling device comprises a heat exchanger, a temperature detection element, a driving pump, a first control valve, a second control valve, a flow detection element and a third control valve. According to the cold point cooling device, the second control valve can be correspondingly and selectively opened and the third control valve is closed or the second control valve is closed and the third control valve is opened according to actual use requirements; water for injection can sequentially pass through the first channel of the heat exchanger, the driving pump, one end of the first control valve and the second control valve correspondingly at the first preset temperature or the second preset temperature and flows out of the water outlet end of the main pipeline, and it is guaranteed that no blind pipe exists in the cold point cooling device; meanwhile, the flow speed of the water for in