The hazard source and leakage risk factor identification is carried out for certain jacket platform, the fault tree is used to deduce the deep cause of the leakage accident, the method of fuzzy theory combined with expert evaluation is used to evaluate the probability of the leakage accident, and the quantitative risk level of the explosion accident is obtained according to the event tree method, so as to provide reference for the risk control of oil and gas leakage and explosion in the process of platform disassembly. The results show that: most of the minimum cut set in the fault tree is single event, that is, there are many direct factors leading to the leakage accident; the fuzzy probability of oil and gas leakage in the process of jacket platform disassembly is 1.706×10?2; considering the most dangerous situation, the explosion probability is 2.732×10?6, which is a small probability event; there are many risk factors in the process of platform disassembly and lack of reference of accident statistical data, and the risk level of oil and gas leakage and explosion can be reasonably obtained by fuzzy fault tree method combined with event tree method.