Based on fast gas chromatograph and time-of-flight mass spectrum technology, fast gas chromatography/electron impaction source of time-of-flight mass spectrometer (FGC/EI-TOF MS) is developed. The FGC/EI-TOF MS is mainly composed of a sample system, a GC separation system, a GC-MS interface, an electron impaction source, a vertical introduction of reflection time-of-flight mass analyzer, a data acquisition system and hardware control system. A vaporization chamber, heating film of GC and three-wall-tube line are built. After the optimization of EPC, temperature of GC, and important voltage parameters, Alkanes standard gas mixtures are studied, and fast seperation and accurate classification different kinds of organic compounds are eventually realized rapidly and accurately. At last, the FGC-TOF MS is applied to test the characteristics of benzenes and isobutane standard gas mixtures. The results indicate that mass range is 4～502 amu, resolution is better than 500, detection limit is 500 ppb, analysis time is less than 5 min, reproducibility RSD is less than 10%, dynamic range is four orders of magnitude.