NHFJ FPSO performs the first inter-regional displacement and reuse in China, which needs to carry out depreciation and reconstruction and calibration of the Internal turret single point mooring system. This paper takes the disconnectable turret mooring(DTM) buoy lifting top as the research object, takes the limit state method as the calibration criterion, and carries out the relevant working condition analysis; compares and analyzes the three kinds of bolt models of solid element, beam element and beam connection; establishes the finite element analysis model, and analyzes the strength of the lifting structure. The results show that: the beam connection bolt model has good applicability in the structural analysis of the lifting top; the overall structural strength of the lifting top meets the design requirements.A set of practical procedures is established for the design and analysis of the lifting top. The developed analytical method can provide a reference for the structural design of a DTM buoy lifting top.