To address the issues of buffeting and slow response in the sliding mode control system of surface mounted permanent magnet synchronous motors, a control strategy combining a novel sliding mode controller with an improved sliding mode observer was proposed. A new approach law was introduced, utilizing the tanh function as the switching function to ensure smoother transitions. Furthermore, the incorporation of a terminal attractor was aimed at enhancing system convergence speed and improving control quality. An improved sliding mode observer was designed to replace the symbol function with a continuous function, compensating for observation errors, reducing buffeting effects, and enhancing observation accuracy. A simulation model of a double closed-loop speed control system based on the new sliding mode controller and improved sliding mode observer was established, and comparative simulation experiments were conducted with a proportional-integral control system and a sliding mode control system based on an exponential reaching law. The simulation results indicate that the proposed control strategy effectively reduces buffeting effects, improves system convergence, and enhances the ability to track desired signals.