Along with the development of urban construction and industry requirement, more and more natural gas has been transported by pipelines. During the transportation, the leakage of the natural gas would be happened because the gas pipelines may be ruptured by the inner or outer factors. If the concentration of the mixture gas composed by natural gas and air reaches the burning and/or explosion limit, it will possibly deal to the fire and/or explosion accident resulting in casualties and serious loss of property once there is a fire source in the surroundings. Therefore, the relevant research on the risk analysis and evaluation to the pipeline carrying the natural gas has been focused in the field of safety engineering in recent years. It is well recognized that the more challenging accident is a jet-fire, wherever pressurized, or pressure liquefied flammable materials are handled, so it is necessary to carry out the evaluation on the jet fire and its preventing and controlling measures. In this paper, the model of the jet fire is built firstly, and then the jet fire consequence evaluation on the natural gas pipelines is processed, and aided by the computer-assisted program MATLAB, the relevant datum have been processed and the influenced areas to person and equipment have been charted; finally, the corresponding preventing and controlling suggestions to guarantee the safety of the transportation have been proposed in this paper. The results of the study are practically significant to the risk assessment and safety management of the natural gas pipeline. (C) 2013 The Authors. Published by Elsevier Ltd.