Since an X-ray Free Electron Laser (XFEL) facility is a linac-based single-user machine, a multi-beamline mode of operation, which improves the efficiency of user experiments, is critical for accommodating users' rapidly increasing demand for beamtime. A key supporting technology is a highly stable pulsed power supply (PS), which enables stable XFEL operations by precisely switching the beam route. We developed a high-power pulsed PS to drive a kicker magnet installed in a SACLA's beam switching system. SiC MOSFETs were adapted as switching elements to reduce the required size and to increase the electric power efficiency. The PS we developed provides two key capabilities: (i) a high current stability of 20 ppm (peak-to-peak) at a peak power of 0.24 MW and (ii) generation of controllable, bipolar, and trapezoidal current waveforms at 60 Hz. This paper describes the overall concept, the detailed design, the performance achieved, and the initial beam test results.