Constant-temperature control system for constant-temperature tank

A constant-temperature control system for a constant-temperature tank comprises tank bodies, a hot water insulation water tank and a cold water insulation water tank. Inner coils are arranged in the tank bodies, and a plurality of the tank bodies form a tank group. A water outlet of the hot water insulation water tank is communicated with inlets of the inner coils of all the tank bodies through first tubes, and the first tubes are communicated with a water outlet of the cold water insulation water tank. Outlets of all the tank body inner coils are communicated with a water inlet of the hot water insulation water tank through second tubes which are communicated with the cold water insulation water tank, and the first tubes are communicated with a water pump. When the hot water insulation water tank temperature is lower than 70 DEG C, the hot water insulation water tank performs heating automatically and stops heating automatically when the temperature reaches 85 DEG C; when water in the hot water insulation water tank is not enough, an electronic valve is opened, water flows into a hot water tube automatically, and the electronic valve is closed automatically after the hot water tube is full of water.