Abstract: Injury margin is a key index in calculating the degree of suffering of domestic industry in the application of antidumping, and an important gist on the decision of antidumping tax. Based on methods of counter-fact, some analysis in extending the CADIC mode are given by considering more factors, using method of AHP to colligate. It is shown in conclusion that the extending mode can be applied in calculating the injury margin in the antidumping practice, well quantifying the suffering of the domestic industry all-sided.