Abstract: Power optimization design of silicon microheater of mine-used MEMS methane sensor was carried out by use of ANSYS finite element software. Firstly, a calculation model of silicon resistivity within certain temperature range was built on basis of known doping concentration. Then an orthogonal test for dule-cantilever type silicon microheater with U shape was carried out according to the calculated resistivity results in ANSYS software, which took doping concentration, distance between two cantilevers and cantilever width as influence factors, so as to research influence of different factors on power of silicon microheater. The test results show that cantilever width and doping concentration are main factors influencing the power of silicon microheater, while distance between two cantilevers has little influence. The power of silicon microheater decreases with decrease of cantilever width, and increases first then decreases with increase of doping concentration. Power of silicon microheater can achieve the optimal value when cantilever width is 25 μm, doping concentration is 1019 cm-3 and distance between two cantilevers is 10 μm at 600 ℃.