The performance of magnetic devices such as transformer and inductor significantly affect the parameters of power supply. Aiming at the problems of poor consistency and low efficiency in making the air gap of the magnetic core of E-type transformer, a finite element analysis model was established for different dispensing schemes, and the shear mechanism of epoxy insulating non-Newtonian fluid with high viscosity was analyzed. The results show that the consistency and processing efficiency of the magnetic devices can be improved by reducing the size of the glue dots, or changing the shape and distribution of the glue dots. By using automatic dispensing process to control the radius and center distance of glue dots accurately, a transformer meeting the requirements of inductance is made, which improves the processing efficiency and verifies the correctness of simulation and mechanism analysis. A high-precision and high-efficiency manufacturing process for torus dispensing and magnetic devices was obtained.