Abstract: In operation progress of offshore exploratory well,independent wellhead brace device is used.In order to reach well control safety and increase drilling depth further,wellhead system stability of exploratory well is analyzed.In this paper,research on wellhead system stability of offshore oil self-elevating drilling platform exploratory well is introduced,the matching equipment technology and operation points such as wellhead casing head,offshore water isolation tube,mudline suspension flow,wellhead suspension system,and so on are analyzed and researched by wellhead counterbalance and conventional well structure,and measures taken to ensure wellhead support flow stable are found.By field example analysis,the relevant technical guidance will be provided for exploration drilling operation in future to reach higher safety effects and economic benefit.