In this paper, thermo-electro–elastic behavior of a hollow cylinder made of carbon nanotubes bundles–reinforced electro-active polymer considering the hierarchical structure of carbon nanotube bundles is investigated. Material properties of carbon nanotube bundles are calculated on the basis of the rule-of-mixtures, and material parameters of the composite are computed in accordance to the self-consistent micromechanical model. Utilizing the finite difference method and numerical solutions for thermo-electro–elastic behavior of the carbon nanotubes bundles–reinforced electro-active polymer hollow cylinder under thermal, electric, and mechanical loads are obtained. Numerical examples show the influences of electric load, thermal load, and material properties, geometric parameters, and boundary conditions on the thermo-electro–elastic behavior of carbon nanotubes bundles–reinforced electro-active polymer cylindrical structures.