Abstract: In this paper, the problem of thermal buckling of thin spherical shells of functionally graded materials composed of metal and ceramics was studied. The stability equation of axisymmetric spherical shell was derived by the tensor method. The thermal constitutive equation was applied to the stability equation of the spherical shell, and the thermal buckling equations of the spherical shell were obtained. The effects of external pressure and temperature were considered. The thermal buckling of simply supported spherical shell was studied by using Galerkin method.The change tendency of the critical pressure and the critical pressure of the thickness of the thin shell and the change of the physical parameters were analyzed.With the change of the thickness, physical property parameter, temperature difference between inside and outside surface, the change tendency of the critical temperature and the change of the critical pressure were presented.