The product structure of BMC stator mould is as follows: there is an iron core in the middle. When forming, the iron core is heated to 100 ℃ as an insert and put into the mould, so it can be seen that the requirements of product size and position accuracy are very high. In addition to the dimensional accuracy of forming parts, the design of gating system, exhaust and heating parts and die rigidity should be guaranteed. The overall structure of the die adopts a single parting surface, one mold, four chambers, and a balanced layout. Because of the use of angle injection machine, the main runner is cylindrical, the cross-section of each sub runner is circular, and the gate is a rectangular narrow side gate. The mold exhaust adopts the method of active air extraction, and an exhaust groove is arranged around the mold cavity, which is connected with the vacuum pump through a pipeline. During the design, attention should be paid to the flatness of the parting surface, and the fit clearance between the core, insert and top bar should be appropriate, otherwise the air extraction effect will be affected. The mould is heated by 14 900W electric heating rods with a total power of 12.6kw to ensure that the working temperature of the mould is 120 ℃, and a temperature measuring device is set at the same time. The mould cavity adopts the structure of integral inlay and local inlay, which not only ensures the dimensional accuracy of the products, but also facilitates the processing. Cr12MoV is selected as the mold forming part material. Through ultrasonic flaw detection, the hardness of heat treatment is 54-58hrc, and the surface roughness Ra = 0.1-0.05 μ M. The BMC stator mould has been proved by production inspection that its structure design is reasonable and the action is reliable.With high the manufacturing precision, the surface luster of this BMC mould is high, and the dimension precision is high. The internal quality and the electrical performance completely meet the design requirements.