There are high reliability requirements for the MEMS oil pressure sensors because of worse automotive application environment.A new type MEMS oil pressure sensor based on ripple membrane isolating technique is designed.The effect of the ripple membrane and the cavity structure of filling oil on sensor performance is analyzed.The theory analyzing and experimental results demonstrate to design suitably the ripple membrane and the cavity structure

reduce cavity volume and purify silica oil are a key to improve oil pressure sensor performances.The measuring precise of developed sensors is superior to 1.5 % at-40～125 ℃ and 0.6 MPa.