Electric vehicles were gradually used in people’s daily transportation, and the requirements of their technical reliability and safety were very high. The motor controller was a device that converted the battery DC power supply to the three phase AC power supply, and then drove the permanent magnet synchronous motor (PMSM) of electric vehicles. A PMSM controller based on Renesas microcontroller was designed. Analysis was carried out from the aspects of component selection, hardware protection structure principle, printed circuit board (PCB) layout, control algorithm, structural strength and thermal analysis. Finally, the prototype controller was produced and the experimental platform was built. The efficiency characteristic test, power generation test and temperature rise test were performed on the PMSM controller. The experimental results verified the rationality of the design.