A passive and wireless pressure sensor based on SAW has been designed in this work.Firstly,the principle of SAW one port resonator was presented. Secondly,the principle of SAW pressure sensor was analyzed.The sensitive structure based on similar both ends fixed beam has been chosen and the simulation and analysis of the sensitive structure have been carried out by ANSYS software.SAW pressure sensor has been modeled and simulated by using Mathcad software.The tested results show that the fabricated sensor has the features of high sensitivity,very small errors and good pressure frequency.