In order to study the law of NO emissions from co-combustion of plastic powder and rice hull, the co-combustion experiments were performed in CFB designed by ourselves. The influences of combustion temperature, the ratio of plastic powder to rice hull and stoichiometric coefficient on the emission of NO were studied. Experimental research showed that NO emissions are increasing with the increase of temperature, NO emissions are decreasing with the increase of ratio of plastic powder to rice hull, and the NO emissions was lower when co-combustion than the weighted arithmetic mean of NO emissions when these two fuels combusted separately, NO emissions will be decreased with the increase of stoichiometric coefficient. In order to search the general law of NO emissions from co-combustion of plastic powder and rice hull, a predicting model of NO emissions based on radial basis function neural network was set up and the forecasted results showed that this model was accurate.