Abstract: For the application requirements of MEMS sensor with high precision and sensitivity, a MEMS thermal and vibration isolator is designed to adapt to complex working conditions and reduce the influence of external environment on the sensor. MEMS sensor installed in the center of the isolator and connected to the base through the suspension beam all around. According to the characteristics of being sensitive to high frequency impact and temperature, the isolator is able to block external shock waves and thermal via suspension polymer beam structure due to the low thermal conductivity and Young modulus of polymer. More than this, external low-frequency acceleration can be fed back. The working performance of MEMS sensor is stable and the environmental adaptability can also be improved. Finite element simulations have been carried out to indicate the temperature, frequency and dynamic responses under the influence of thermal-mechanical, in addition,the simulation results are compared with different polymer materials and structural parameters. At last, the optimization scheme is adopted from processing, heat insulation, vibration isolation and structural strength. This design can provide a reference for environmental adaptability of MEMS and expand its application scope in military weapons and equipment, aerospace and aviation fields.