The invention relates to the technical field of low temperature and constant temperature, and discloses a low-temperature and constant-temperature liquid circulating device and a
dewatering method thereof. According to the low-temperature and constant-temperature liquid circulating device and the
dewatering method thereof, on one hand, an ice
crystal filter and a plurality of stop valves are additionally arranged in a circulating liquid loop, so that a pair of parallel standby
branch and common
branch can be formed, when circulating liquid flows through the common
branch where the ice
crystal filter is located, mixed water can be effectively intercepted and collected due to the fact that the water is frozen into ice cubes, the phenomena that a capillary pipeline in a
temperature control liquid pipeline is blocked in the follow-up circulating process, and component cooling faults are caused can be solved, the
temperature control stability is guaranteed, on the other hand, a heater, an exhaust connector, a
nitrogen connector and a plurality of valves are continuously and additionally arranged for the ice
crystal filter, when the standby branch is switched to replace the common branch to keep the circulating liquid loop to be connected, water in the ice
crystal filter can be heated and purged in an isolated mode, and therefore on the premise that the circulating liquid loop is not interrupted, the maintenance time can be shortened, the maintenance operation can be reduced, and the equipment productivity loss can be reduced.