Based on the corresponding relation of characteristic parameters between the perturbation wave of boundary layer and the surface erosion corrugation wave of fluid-pass section, the anti-erosion design idea is proposed, which can realize the synchronistic fluctuate of elastic coating channel border with the perturbation of boundary layer, and change the passive state that channel border bears particle's impacting into that the channel border collision contacts with particles on its own initiative. The condition of realized synchronous fluctuation of elastic coating channel border with the perturbation of boundary layer is analyzed. On the basis of analysis result, the method of determining the material parameters of elastic coating is proposed.