Abstract: This article establishes an adaptive phase field model for the fracture problem of geometric thin shell structures based on Kirchhoff-love shell theory and adaptive PHT isogeometrice analysis. In the analysis process, from the perspectives of energy and fracture mechanics, the differential equations of the phase field model for Kirchhoff-Love thin shell fracture problem were derived based on adaptive PHT isogeometric analysis, and the PHT spline basis function was used as the interpolation function to discretize the displacement field and phase field. On the one hand, Kirchhoff-Love thin shell theory does not require rotational degrees of freedom, greatly reducing the computational times; On the other hand, PHT splines are geometrically accurate and satisfy the continuity of Kirchhoff-Love thin shell theory. At the same time, PHT splines not only inherit the advantages of NURBS splines, but also have local subdivision. Finally, corresponding programs were written to compare and analyze classic numerical examples, and the correctness and convergence of the fracture phase field model were discussed.