With the economic development and people's living standards improve; natural gas has become an important source of urban life and industrial energy. However, influenced by the factors of failure, failure of natural gas pipelines leakage accidents have occurred, causing serious casualties and property losses. Therefore, the risk assessment, maintenance and management of natural gas pipeline, ensure the safety and reliability of gas supply system, has become a hot issue of research at home and abroad. In this paper, based on the domestic and foreign research, considering the internal gas pipeline pressure redistribution and external accident of the individual risk and social risk caused economic losses, the comprehensive consideration of the influence of various factors on quantitative risk assessment method for pipeline safety. Through empirical research and analysis, the results show that: The risk assessment methodology can be predicted gas pipeline leak and the possible consequences after the spill occurred, which has practical significance for the prevention of the natural gas pipeline accidents as well as how to effectively control the impact of disasters after the accident.