The conventional crushing process has low productivity and coarse product grain in the production of Chifeng Chaikuang company.In light of that,based on semi-industrial test,closed-circuit high pressure roller mill screening process is applied and achieves good production performance.The production practice shows that the process performs fit,effectively improving the energy consumption structure of the metallurgical system,optimizing production index,improving productivity,lowering production cost,with the crushing productivity increased by 50 %,product grain P90 decreased from -11 mm to -6 mm,metallurgical production cost lowered by 11.16 %,saving nearly ten million yuan per year and creating significant social and economic profits.