The self-repair technology of composite materials and self-repair principles of microcapsules were introduced in this paper. The weight loss and noise reduction of machine in food machinery could be achieved by using the composite gear made of self-repair materials of microcapsules. The effect of self-repair microcapsules on the vibration of gear made of composite materials was revealed by analyzing noise data under different temperatures during the vibration of new gear made of composite materials. The results showed that self-healing microcapsules reduce the friction of the gear noise.