A method for system-level simulation between microbolometer designing and Read-Out Integrated Circuit(ROIC) was studied. Three-dimensional(3D) structure modeling of the microbolometer was built. Thermal capacity, thermal conductivity and resistance of the model were obtained from thermoelectric coupling Finite Element Method(FEM) based on the model. An electrical equipment circuit of microbolometer which contains these three parameters was established. By using Verilog-AMS language, the electrical equipment circuit was described as a reduced-order macro-model. Then, the reduced-order macromodel was compiled in cadence to form IP unit of microbolometer, which could be used and identified in cadence. Systemlevel simulation between microbolometer and ROIC was accomplished. Key performances of the device, including input and output characteristics, were obtained in simulation and verified by experimental results. A method for system-level simulation between microbolometer designing and Read-Out Integrated Circuit (ROIC) was studied. Three-dimensional (3D) structure modeling of the microbolometer was built. Thermal capacity, thermal conductivity and resistance of the model were obtained from thermoelectric Coupling Finite Element Method (FEM) based on the model. An electrical equipment circuit of microbolometer which contains these three parameters was established. By using Verilog-AMS language, the electrical equipment circuit was described as a reduced-order macro-model. The reduced-order macromodel was compiled in cadence to form IP unit of microbolometer, which could be used and identified in cadence. System performance simulation with microbolometer and ROIC was accomplished. Key performances of the device, including input and output characteristics, were obtained in simulation and verified by experimental results.