Abstract The dynamic response of spherical sandwich shells with aluminum face sheets and aluminum foam core under external air blast loadings were investigated numerically by employing the LS-DYNA. To calibrate the numerical model, the experiments of cylindrical sandwich shells were modeled. And the numerical results have a good agreement with the experiment data. The calibrated numerical model was used to simulate the dynamic response of spherical sandwich shells subjected to the external air blast loadings. It is found that the spherical sandwich shells have a better performance than that of the cylindrical sandwich shells in resisting the blast loadings. The structural dynamic response process has been divided into three specific stages and the deformation modes have been classified and discussed systematically. According to parametric studies, it is concluded that with the decrease of radius of curvature, increase of the thickness of foam core and face sheets and decrease of blast intensity, the blast-resistance is increasing obviously; keeping the thickness summation of front and back face sheet almost constant, a big thickness of front face sheet will improve the blast-resistance performance. These simulations findings can guide well the theoretical study and optimal design of spherical sandwich structures subjected to external blast loading.