Polymeric membranes with diverse structures have attracted much attention as new materials for nonlinear optical devices. In this report, a novel oligomer of poly (aromatic ether sulfone) (OAES) has been synthesized and characterized. The electronic structure as well as linear and nonlinear optical properties has been studied by density function theory. The effect for general nonlinear optical polarizability of various condition has been further researched such as absence of side chains and introduction of phenyl substituent on side chains. The static and frequency-dependent hyperpolarizabilities of OAES and its derivatives have been calculated. This work interprets an efficient adjustment for the frequency response and the intensity of nonlinear optical polarizability can be achieved by regulating the structure of system, which provides a new potential for the application of oligomeric materials on nonlinear optical field.