Abstract: Linking the moderate principle of intrinsic safety theory with risk management of CNG cylinder accident, intrinsic safety theory and its basic principles are introduced. The CNG cylinder accident form is expounded, and the safety reliability of CNG steel cylinders, twined gas cylinders and all composite material cylinders is analyzed in this paper. According to the moderate principle of intrinsic safety theory, the measures and methods to prevent the accident of vehicle CNG cylinder are discussed, and the relationship of intrinsic safety principle and the precautionary measures of vehicle CNG cylinder accident are expounded. The established regulatory measures for accident analysis and control have been perfected and complemented.