Abstract: A MEMS capacitive micromechanical pressure sensor with high linearity is presented, which is based on a fixed spherical cap electrode and a multiple membrane. In this device, the touch process of electrodes starts at the beginning of measuring range, and a structure of hole made by DRIE is added. The novel device can enable a good linearity during the whole measuring range. The analysis of membrane thickness to touch status and linearity is performed, so that the novel structure is verified to be effective. Furthermore, the fabrication process of this device is proposed and introduced. This high-linear micromechanical pressure sensor can provide a good choice to tire pressure monitoring system (TPMS), which will work at the press range of 100 kPa to 800 kPa.