An investigation was carried out on iron cast with quadratic regression rotary combination test. The mathematical model which characterizes the relationship among parameters of grit-blasting, i.e., distance, pressure and angle, and adhesive strength was established. The influence of dual factor combination on adhesive strength was studied by dimension decreasing standard analysis. Results show that, there is an optimum value of adhesive strength on scope of test parameters; the pressure should be as high as possible; it is improper that the distance and angle are too higher or too lower; the technology of grit-blasting could greatly meet the demand of surface pretreatment for arc-spraying.