Optical frequency combs are pivotal in the realm of precise measurement and time-frequency standards. As technology advances, traditional optical frequency combs are trending towards miniaturization and integration, leading to the emergence of innovations such as micro-optical frequency combs and micro-optomechanical coupling frequency combs. Leveraging the similarities between photons and phonons, micromechanical frequency combs based solely on mechanical vibrations present novel opportunities for sensor technology, quantum information communication, and applications in extreme environments. This paper first introduces a numerical simulation model of micromechanical frequency combs. Based on it, it then elucidates the generation mechanisms of these combs, which include parametric excitation, internal resonance, contact and impact effects, negative dissipation, and negative nonlinear friction. Furthermore, from a perspective of practical application, this paper aims to enhance the reader's understanding of the extensive applications of micromechanical frequency combs in related fields, their distinctive characteristics and advantages, and provides a summary and outlook on future development directions.