Abstract: Martian atmosphere density measurement instruments need new sensors which have low power consumption,high sensitivity and fast response speed.Therefore,this paper proposes a new method to fabricate atmosphere density sensor basing on aerodynamic heating principle,and verifies the theoretical feasibility by judging the gas flow state,caculating the thermal power density ＆ pressure generated by collisions of molecules with thermal devices and analyzing the noise and performance.The sensor is suitable for measuring the Mars’ atmospheric density at the altitude from 90 km to 400 km.Its thermal response time is 122 ms and the lowest detectable pressure is 2.05×10^-8 Pa.