The underground gas storage in salt caverns

mined by drilling and water dissolving solution

has low visibility and high difficulty of cavern form controllability

so it is a very significant measure to carry out scientific stability evaluation on deformed gas storage for ensuring its safe operation. In this study

the variable weight theory and relative difference function are introduced to build the assessment model which can be suitable for salt cavern stability assessment. Based on the sonar data of salt cavern shape

the 3D model is built up firstly in numerical simulation calculation

and the simulation results are used as the marking standard of relational assessment index. This model is applied to the stability assessment process of some salt cavern in Jintan; and improving measures for safety are carried out on the basis of assessment results. By a comparison of these results with some others

it is shown that the stability assessment model is more reasonable

as the evaluation index weight has been recalculated by variable weight theory; and this method has relatively better applicability in cavern stability assessment of gas storage in salt cavern.