A new inductorless control method based on a new integral differential sliding mode controller and a new sliding mode observer is proposed to address the problems of excessive overshoot of the speed loop proportional-integral control (PI) and high-frequency jitter of the conventional sliding mode observer (SMO) in permanent magnet synchronous motors. The method replaces the PI controller with a new differential-integral sliding mode controller, uses continuous function instead of switching function to reduce jitter, designs the sliding mode observer with exponential convergence law and estimates the counter-electromotive force, and designs the adaptive law according to the counter-electromotive force to avoid the use of low-pass filter to obtain more accurate rotor position. Finally, the model is built by MATLAB/simulink, and the results show that the method has the characteristics of jitter reduction, no overshoot, and accurate rotor position estimation, and the maximum error of speed is reduced from 18 r/min to 2.5 r/min, and the error of rotor position is reduced from 0.048 rad to 0.021 rad.