The horizontal stability of the pontoon in the floating wharf is related to the operation safety of the tourist wharf and the personal safety of tourists. Before the issuance of JTS 165-7—2014 Code for design of marinas,the calculation principle of the floating stability of the pontoon in the engineering design was based on the calculation principle of the floating stability of the gravity caisson. Based on combing the calculation principles of caissons and pontoons,this paper uses the research methods of theoretical analysis,formula derivation and engineering case verification to verify that it is reasonable and feasible to calculate the floating stability of pontoons by using gravity caisson floating stability calculation principles. The research results of this paper have important reference value for the follow-up research and design work.