The invention belongs to the technical field of thermal crystallization for evaporation of a sodium gluconate solution, and particularly relates to a device and a method for evaporation and crystallization of the sodium gluconate solution. A system for recompressing and utilizing secondary steam produced through evaporation is adopted, the secondary steam produced by an evaporation system is compressed and heated by an energy-efficient steam compressor, the enthalpy value of the secondary steam is increased, the secondary steam with the enthalpy value increased enters the evaporation system to be used as a heat source to be recycled, most live steam is replaced, and the live steam is only used for replenishing the heat loss and replenishing the enthalpy required by the incoming and outgoing material temperature difference, so that the live steam consumption of evaporators is substantially reduced, and energy is saved.