We propose a polysilicon Seebeck coefficient test structure for a thermoelectric micro-generator for a wireless sensor nodes (WSNs). The polysilicon Seebeck coefficient test structure consists of an etched polysilicon, a polyimide layer, and a special structure interconnected by metal. The temperature measuring resistor is designed as a folded structure, which can increase the resistance value for testing. At the same time, four measuring electrodes are designed for each temperature measuring resistor, and the four-probe method can be used to accurately measure the resistance with less error. Since the Seebeck coefficient of the semiconductor material is much larger than that of the metal, the Seebeck coefficient of the polysilicon material is approximately equal to the Seebeck coefficient of the polysilicon/metal thermocouple. The test structure is extremely important for guiding the design of integrated generators.