The invention relates to the technical field of workpiece machining, especially relates to a planetary reducer shell machining process and a drilling mechanism. The process comprises a rack, the rackis provided with a working table, a driving component, a mounting plate, a drill bit, a driving part and a lifting part, the working table is provided with a clamp, the mounting plate is provided witha blowing device, the drill bit is provided with a through groove, the through groove comprises a groove body, a first notch and a second notch, the first notch is arranged at the first sliding rail,a plurality of heat conducting box and a driving piece, the first sliding rail is provided with a first sliding cavity and a limiting piece, the second groove is arranged at the mouth of the containing piece, the heat conducting boxes are filled with cooling mediums, the cooling mediums will rapidly cooling the drill bit, the driving piece and the containing piece realizes the heat conduction boxthe automatic material, and heat conduction box may be re-cooled so that the repeated utilization. The process ensures the cooling effect of the drill bit, saves resources, reduces the labor intensity of workers.