To reduce the torque ripple, this study investigates the effect of different slot/pole ratios and air gaps on the torque ripple of the motor. Under the same size, same speed, and the same excitation, the performance analysis of the electric excitation concentrated winding motor with 12/10, 18/10, 30/10 is carried out. First, the finite element analysis of the motors with different slot/pole ratios is performed and the influence of the uniformity of the air gap of the motors on the cogging torque is comparatively analyzed. Through comparison, it is found that an appropriate slot/pole ratio can reduce cogging torque and the harmonic content of back EMF, and from the perspective of cogging torque, fractional slot motors are lower than integer slot motors. The use of non-uniform air gap can reduce the content of air gap magnetic density harmonics, therefore further reducing cogging torque and torque ripple. After finite element calculation, the inductance of these three kinds of motors and their influence on torque are analyzed. Finally, it is found that the non-uniform air gap has a more obvious effect on reducing the torque ripple of the motor. The torque ripple percentage of the 12/10 motor has been reduced from 10.6% to 4.2%.