The self-lubricating mute gear comprises an annular body, tooth bodies are integrally formed on the circumference of the annular body, the annular body and the tooth bodies are made of metal, and nylon layers are arranged on the faces between the tooth bodies; an annular oil cavity is formed in the center of the annular body, an oil uniformizing device is arranged around the oil cavity, and the preparation process comprises the steps of S1, blank taking and milling, and S2, mold injection molding; according to the gear, the oil cavity integrally formed with the gear body is formed, and the oil homogenizing device is arranged outside the oil cavity, so that when the gear runs at a high speed, lubricating oil can be sprayed out from the side wall in the oil cavity under the action of centrifugal force, is uniformly dispersed out through the umbrella-shaped oil guide sheet and slowly permeates into the gear body, and the lubricating oil can be uniformly dispersed out through the umbrella-shaped oil guide sheet; the gear can be lubricated in real time; nylon is compounded on the meshing face of the gear, it is guaranteed that the wear rate of the gear is reduced, and due to the fact that the gear is made of a metal material, the metal material is low in shrinkage rate, and precision can still be kept.