Low-temperature constant-temperature device and temperature control method

The embodiment of the invention relates to the technical field of low temperature, in particular to a low-temperature constant-temperature device and a temperature control method. The low-temperature constant-temperature device comprises a shell; the storage tank is arranged in the shell and used for storing low-temperature liquid; the heat bridge is arranged in the shell, a cavity is formed in the heat bridge, and the cavity communicates with the storage tank; the electric heater is used for heating the thermal bridge; the adjusting assembly is used for adjusting the liquid level of the low-temperature liquid in the cavity; the refrigerating temperature and the temperature changing speed of an object located on the heat bridge are controlled through cooperation of the electric heater and low-temperature liquid in the cavity. According to the low-temperature constant-temperature device, rapid and stable control over the temperature of the object on the heat bridge at high temperature and low temperature can b