The application of electrospinning fabrication technology in micro/nano sensor production was investigated. Mixed solutions of praecursor bodies PVP(Polyvinyl Pyrrlidone)/Zn(Ac)2 and PEO(Polyoxyethylene)/Zn(Ac)2 were used as the electrospinning materials to make a precursor nanofiber. The precursor nanofiber was calcined at 500 °C in the air to remove polymers and the Zn(Ac)2 was thermally decomposed and oxidized into ZnO. X-ray diffraction (XRD) was used to charaterize the components of a ZnO nanofiber. The sensing response of a ZnO nanofibrous gas sensor on the ethanol and acetone vapors were tested. The test results indicate that the average diameters of ZnO nanofiber made from PVP/Zn(Ac)2, PEO/Zn(Ac)2 precursor are 308 nm and 184 nm, respectively. XRD spectrograms show that the ZnO nanofiber with high purity can be obtained from a blended precursor nanofiber through thermal oxidation. The response time of the ZnO nanofibrous sensor on the objective gas is less than 1 s at room temperature and its sensitivity increases with the increment of gas concentration. Furthermore, the ZnO nanofiber made from PEO/Zn(Ac)2 precursor shows a roughness surface, a larger specific surface area and higher sensing sensitivity, and the maximal sensitivity of ZnO nanofibrous gas sensor on ethanol and acetone vapor have been up to 215.69 and 118.13, respectively. This work presents a novel method for the integration fabrication of semiconductor micro/nano gas sensors.