In view of the problem that seismic damage evaluation for reinforced concrete structure are difficult to quantify, a new model for seismic damage evaluation was established by five-element connection number based on set pair analysis in the paper, which took internal damage index, maximum inter-storey drift, number of inelastic cycles and energy-concentrated quotient as evaluation factors. All indexes can be summarized into five-element connection number. Four different types of structure are analyzed on the model with more satisfactory results. Compared with the matter-element analysis evaluation method, this model is perfect, the evaluating result is more reasonable and its resolving power is higher. By this practical example, the model proved to be effective in seismic damage evaluation on reinforced concrete structure.