Microcavity optical frequency combs exhibit low power consumption, integration, and tunable comb spacing, and they have been widely used in many fields. The technology for processing silicon-on-insulator (SOI) materials is compatible with the existing complementary metal-oxide-semiconductor (CMOS) process, making it one of the most promising photonic platforms. In this study, a silicon-based micro-ring resonator with a ridge section was designed, and the effects of various geometric parameters on the dispersion of the micro-ring resonator were investigated. The thermal dynamic equation of the micro-ring resonator was numerically solved, and the effects of different parameters on the thermal dynamic influence of the micro-ring resonator were analyzed. The Lugiato-Lefever equation (LLE) model was solved numerically. Because the thermo-optic effect was ignored in the theoretical research on SOI microcavity optical frequency comb, the influence of the thermo-optic effect on the generation and evolution of the optical frequency comb was analyzed. The numerical results show that at 0?0.16 °C, the maximum power of the light field increases by 22% in the time domain, and the optical frequency comb broadens by 221 nm in the frequency domain. Finally, the output spectrum of the optical frequency comb under two kinds of thermo-optic effects was analyzed. The results show that the bandwidth of the optical frequency comb is expanded by 353 nm compared with that at 0?0.16 °C when the temperature range of the thermo-optic effect is 0?0.32 °C.