The invention discloses a sodium-sulfur battery module heat-preservation box, belonging to the field of chemical energy storage. The sodium-sulfur battery module heat-preservation box is composed of a bottom plate, two side plates, two end plates and a box cover; the box is internally divided into four heat-preservation rooms which are arrayed in two rows and two arrays in a matrix shape by using a long heat preservation plate and a short heat preservation plate; each heat-preservation room uses one bottom heating plate and one independently-used side heating plate; the two adjacent heat-preservation rooms commonly use one public side heating plate by the short heat preservation plate; the two adjacent heat-preservation rooms commonly use one end part heating plate by the long heat preservation plate; temperature control circuits of the independently-used side heating plate, the bottom heating plate, the public side heating plate and an end part heating plate, and peripheral temperature thermocouples are connected with a BMS (Battery Management System); the maximum value thermocouple is arranged on the top face of the edge of the bottom plate and the minimum value thermocouple is arranged at the crossed point of the long heat preservation plate and the short heat preservation plate; the maximum value thermocouple and the minimum value thermocouple are connected with the BMS. The sodium-sulfur battery module heat-preservation box has the technical effects that the temperature difference between any two points of the sodium-sulfur battery module heat-preservation box is controlled within 30 DEG C.