In coal mining equipment, explosion-proof enclosures are often used for explosion-proof purposes, and the safety of the explosion-proof joint surface plays an important role in the safety of the explosion-proof enclosure. Therefore, equipment using flameproof enclosure “d” protection method needs to be designed with bolt fastening on the flameproof surface of the flange, and the design of bolt fastening method has a direct impact on whether the flameproof chamber is explosion-proof. This study used theoretical calculations to calculate the size and quantity of flange flameproof surface fastening bolts, and based on the calculation results, two layout schemes were designed for finite element analysis and comparison. Based on theoretical calculations and simulation analysis, the conclusion is drawn that the theoretical calculation method is relatively accurate. According to the actual situation, the influence of selecting different types of bolts is not significant, and the maximum stress value in this experiment reaches 73% of the yield stress. The design is reasonable and can be used as a reference scheme for bolt design of similar equipment.