Abstract: To address the imbalance between convergence speed and chattering suppression in traditional sliding mode control for permanent magnet synchronous motors, a collaborative control strategy combining a dual-factor dynamic sliding surface and a variable-rate reaching law is proposed. Firstly, an exponential term of the sliding variable is introduced into the sliding mode reaching law, enabling adaptive variable-speed capability during convergence. This accelerates convergence when far from the sliding surface and smoothens the approach near the surface to suppress chattering. Meanwhile, the traditional sign function is replaced with continuous and smooth hyperbolic tangent and saturation functions, effectively reducing high-frequency chattering in the control signal and improving system smoothness. Secondly, a disturbance observer based on the Sigmoid function is designed to estimate and compensate for external disturbances and parameter uncertainties in real time, further enhancing disturbance rejection and control accuracy. Finally, simulation and experimental results demonstrate that the proposed method significantly improves the dynamic response speed, overshoot suppression capability, and external disturbance compensation ability during motor operation.