A method and a device for predicting insulator pollution grade includes acquiring prediction data affecting the insulator pollution grade; acquiring current pollution status of the insulator; predicting the insulator pollution grade based on the prediction data, the current pollution status and an insulator pollution grade calculating model, wherein the insulator pollution grade calculating model at least comprises an initial pollution status variable of the insulator, and a pollutant accumulation prediction and a pollutant reduction prediction based on the initial pollution status variable, at least one of the accumulation prediction and the reduction prediction being associated with the prediction data, and the initial pollution status variable being associated with the current pollution status.