Abstract: Considering that the operation time should be saved as much as possible during the hot work of pipeline in oil and gas station, the time required for nitrogen injection, pipe cutting, welding, NDT and other processes in the hot work of pipeline in station was compared, and it was found that there was much space for time optimization in the nitrogen injection process. For conventional nitrogen injection method, the removal and reassembly of valves, nitrogen injection flanges and other components always result in huge workload and occupy a large amount of hot work time. By referring to the assembling form of flange gasket and changing the internal structure and assembling mode of nitrogen injection device, a fast-assembling type nitrogen injection device for hot work of pipeline in station was developed. With this device, the workload of bolt removal and assembling can be reduced by at least 50% for nitrogen injection, and the time for nitrogen injection process can be saved. Field application shows that, the problems of the nitrogen injection device for the hot work of pipeline in the station, such as inconvenient assembling, time-consuming works and inability to further improve the hot work efficiency, can be effectively handled by using this device, and the device is suggested to be popularized and applied in the hot work construction of pipeline and equipment in the petrochemical industry.