Abstract: In order to evaluate the effect of flue gas desulphurization of coal gangue power plant, this paper selected evaluation indicators of flue gas desulphurization according to certain principles and constructed model of the effect about flue gas desulphurization of coal gangue power plant using BP neural network, and used the model to learn, train and simulation process. The model operated simply and effectively, was able to provide a scientific basis for the evaluation of flue gas desulphurization of coal gangue power plant.