Abstract: The method based on macromodel to process a system-level simulation for Micro-Electro-Mechanical Systems most of which are cross multiple physical coupled energy domains has became a famous research field.For a large scale system function,the matrix subspace projection in order to reduce model order has a broad application recently.The conventional Krylov subspace method could be used only in state-space models which are first-order type.The approach used in our study is known as second-order Krylov subspace theory and can make reduced-order models based on Arnoldi algorithm directly for second-order systems.Using this method the macromodel of electrothermal microgripper is created combined with finite element tools.We took the structure-electro-thermal analysis to microgripper using reduced-order model and the result is exact compared with finite element analysis even more has a few computing consuming and time.