This paper presents the design and testing of a Silicon Carbide (SiC) power module that can operate at 200 ℃ for a long period of time. The overall structure of the module is relatively simple to ensure reliable electrical connections in a high-temperature environment. Silver sintering technology is used to attach the SiC chip to the substrate, thereby reducing its risk of failure under high-temperature loads. In addition, the ceramic substrate material is aluminum nitride (AlN), which is closer to the coefficient of thermal expansion of SiC chips, thus reducing the thermal stress in the interconnection layer. The power terminal and signal terminal are electrically connected to the AlN substrate by an ultrasonic welding process, which results in strong connection strength. The test results of the electrical characteristics of the module after fabrication show that the electrical parameters of the module meet the requirements of the chip manual. Furthermore, the thermal experiment verifies that the designed module can work continuously at 200 ℃, which gives the full advantage to the high-temperature characteristics of SiC devices.