根据实验室设计的单层微测辐射热计所采用的Si3N4和SiO2双层膜复合支撑结构工艺，分别利用力学的等效截面方法和复合材料热导公式，从理论上推导了微桥桥腿正应力和热导的解析表达式.分析在其它因素不变的情况下，仅调整Si3N4和SiO2两者厚度比值(m)对微测辐射热计力学和热学性质的影响,并用ANSYS有限元仿真的方法验证了理论推导.

Based on the technology of monolayer microbolometer, which used Si3N4 and SiO2 double-layer membrane supporting materials, the analytic expressions of the normal stress and the thermal conductivity of the microbridge leg were derived by using the mechanical equivalent cross-section methods and the composite thermal conductivity formula. The influence of the thickness ratio m of Si3N4 to SiO2 on the mechanical and thermal characteristics of microbridge was analyzed when other factors were not changed. At last, the theoretical derivation was verified by the method of ANSYS finite element simulation.