Pattern transformation in periodic cellular structures induces significant property changes under specific external stimuli, resulting in unusual mechanical behavior. This paper proposes an efficient homogenization method for predicting multiple buckling responses of cellular cylindrical shells composed of such pattern-transformation metamaterial. FEM simulations reveal four distinct buckling modes and three kinds of post-buckling processes, achieved through controlled adjustments in the ratio of cylindrical shell thickness to the radius and structural porosity. An efficient homogenization method with the local buckling in the cellular cylindrical shell modeled as an equivalent plasticity in the homogenized shell enables us to predict the critical buckling stress and the post-buckling morphology in good agreement with FEM simulations, analytical analysis, and experiments. The derived solution for the critical buckling load of the cellular cylindrical shells provides practical insights for designing and applying such cylindrical cellular structures.