A gas pressure sensor based on Fabry Perot interferometer(FPI) is proposed and experimentally verified to meet the requirements of gas pressure measurement in industrial production. First,the capillary quartz tube is spliced into a single mode fiber. Then,the capillary quartz tube is accurately cut to a very short length by femtosecond laser. Finally,the polyvinyl alcohol(PVA) film is coated on the end face of the capillary quartz tube to form a gas pressure sensing probe. The total length of the sensing head is only 50μm,which can be used flexibly in limited space and harsh environments. The experimental results show that the sensor can measure the gas pressure of the environment by demodulating the wavelength drift of the reflection spectrum. The gas pressure sensitivity is -4.457 nm/MPa,the linearity is 99.52% and the gas pressure measurement range is 0～0.5 MPa. There is a certain dependence on low temperature for the sensor. While,at high temperature,the sensor is not sensitive and the crosstalk between temperature and gas pressure measurement can be ignored. The sensor has compact structure,high sensitivity,good structure repeatability and small temperature crosstalk,which has a certain application prospect in engineering practice.