The flow field in a rrotating cascade of a centrifugal turbomachine has been analyzed by using a unmerical iteration technique with S 1and S 2 streamsheets.Based on this,anew technique combiningthree-dimensional finite element interpolation and 4th rank RungeKutta method for high order ordinary differential equations is presented and used to solve the three-dimensional equations off motion of solid particles.The gas-solid two-phase flow field in an induced fan of 300MW plant boiler is numerically simulated.It also takes into consideration the influence of defferent particle's diameters and inlet positions on particle impingement,wear and tear with the blade surface and the turbomachine casing.It is helpful for designing the induced fan of plant boiler by avoiding wear and tear fron the gasdynamic point of view.