The invention discloses a double-stage thermoelectric material device, which includes a base and a thermoelectric device body. A groove is opened on the upper surface of the base, and a thermoelectric device body is arranged inside the groove. The thermoelectric device body includes a lower substrate and an upper substrate. , conductive plate, double-stage P-type thermoelectric element, double-stage N-type thermoelectric element and electrode rod, the lower base plate and the upper base plate are symmetrically arranged; by setting threaded columns, rotating shafts, bearings, extruded plates, mounting plates and bolts, in When installing and fixing the thermoelectric device body, the threaded column is driven to rotate by turning the handle, and then the rotating shaft is driven to rotate in the bearing, so that the extrusion plate moves to the left to fix the thermoelectric device body in the groove, and the telescopic rod can squeeze The pressure plate is used to limit the position, which improves the safety guarantee. By using double-stage P-shaped thermoelectric elements and N-shaped thermoelectric elements, thermoelectric materials in different temperature ranges are superimposed and used in parallel, which can make full use of the physical properties of different materials and effectively improve the performance of thermoelectric devices. power generation efficiency.