The existing achievements of grey theory still cannot build a prediction model of discrete grey number with
subjective valued orientation. Therefore, a group of grey forecasting model is built based on the sequences of“core”,“area
of grey cell grid”and“possible values”of standard discrete grey numbers, which realizes the prediction of discrete grey
numbers and their possible values, and then the prediction model of discrete grey number with subjective valued orientation
is built. The model is employed to simulate and forecast the API (air pollution index) of air monitoring point, and a fine result
is obtained, which has a vital significance for extending the applied scope of grey prediction model.