The invention discloses a method for obtaining a model in the impairment area of upper jaw bone: adopting urografin liquid mixed with alginate to produce moulage material which is pressed from cheilion or suffering nasal cavity and fills the impairment area; scanning to obtain the data in impairment area by adopting helix CT; preparing the model in the impairment area of the upper jaw bone through three dimensional reconstruction and rapid molding. The invention resolves the problem of difficult delivery for sufferers who are confined to open mouth, with little pain for sufferers in delivery, completely obtaining the undercut parenchyma in the impairment area with high accuracy for the prepared model in the impairment area.