Parametric vibrations are commonly observed in microelectromechanical systems （MEMS） coupled with multi-physical fields. To study the parametric resonance nonlinear dynamics problems in electrostatically driven micromirror systems， a class of electrostatic comb-driven micromirrors is used as an example to study the parametric resonance response variation of the system un? der different factors by fitting a seventh-order polynomial to the comb capacitance variation and establishing a micromirror dynamics model. The influence of changes in the micromirror’s structural parameters on the torsion angle under static conditions is investigat? ed. The multi-scale method is applied to analyze how system parameters affect the variation in resonance amplitude during the reso? nance state， and numerical verification of system parameter resonance is performed. Finally， the stability of subharmonic paramet? ric resonance in the system is analyzed and verified using the Runge-Kutta method. The results show that subharmonic parametric resonance exists in the micromirror system. Factors such as excitation voltage and capacitance fitting parameters can affect the sys? tem’s resonance amplitude. Damping can alter the system’s instability region， increase the instability threshold， and influence the occurrence of subharmonic parametric resonance in the system.