The invention discloses a cam type lead seal knob mechanism. The cam type lead seal knob mechanism comprises a lead seal knob installed on an upper cover, the lead seal knob is composed of an end cover and a stepped shaft, the end cover is located on the outer side of the upper cover, the stepped shaft is partially located on the inner side of the upper cover, an opening groove is formed in the stepped shaft and is used for being connected with a boss of the inner side of a lower cover, the end surface of the opening groove is in a step shape, two through holes in the radial direction are formed in the outer circle of the end cover and the outer circle of a mounting hole of the upper cover respectively, and the through holes can be inserted into a lead seal. The cam type lead seal knob mechanism is the same as an electricity meter product, the lead seal knob mechanism and the electricity meter product both can be designed through dies, the lead seal knob mechanism can cooperate with large-scale rapid production of the electricity meter products, and the problems of shortage of part supply and the like can be avoided; and in addition, according to the cam type lead seal knob mechanism, the screw-free installation can be realized, the assembly process and the assembly difficulty are reduced, the labor cost is effectively reduced, and the mechanism is suitable for multiple disassembly occasions, is convenient to use, safe, reliable, concise and attractive in appearance and good in popularization and application value in the electricity meter industry.