In this paper, the dynamic characteristics of MEMS gas bearing are investigated. Angular misalignment and rarefaction effect are introduced into the lubrication equation based on FK model. The partial derivative method is adopted to solve the lubrication equation. The comparison of the calculating results between continuous model and rarefied model shows that the rarefaction effect has obvious impact on the dynamic performance of MEMS gas bearing. Then the influence of misalignment on the dynamic coefficients of MEMS gas bearing is studied and the influence laws on 8 dynamic characteristic coefficients are obtained. Furthermore, the limit dynamic performances considering misalignment and rarefaction effect are discussed in detail. •The rarefaction effect is introduced into the dynamic lubricated equation.•The rarefaction effect is introduced into the dynamic lubricated equation.•The analysis shows that the rarefaction effect has obvious impact on bearing’s dynamic performance.•The influence of misalignment on the 8 dynamic coefficients of MEMS gas bearing is studied.•The limit dynamic performances considering misalignment and rarefaction effect are discussed in detail.