Abstract: According to the computer's dataout, the paper points out that D Jolley.drawing mathematical model contains much inborn defect,bears out that D Jolley. model's dataout is not similar with real drawing result,that the characteristic value(q) doesn't control D Jolley. model's similar process.Simultaneously, the paper advances a numerical value similar method on the basis of the expected value body (EVB) drawing theory,and demonstrates that new similar method is simple, exact and feasible based on it's computing result.