Taking the successful modification of domestic cement vertical roller mill in a cement factory as an example, the application of TCDRI new grinding area technology in the modification project of domestic cement vertical roller mill is introduced. By changing the flow rate and movement path of the material on the table, the effective grinding zone is widened, so as to improve the stability of the vertical roller mill, increase production and reduce consumption. This modification adopts the method of online welding, shorten the period of modification. The construction period is 20 days, and the return on investment is high. Under the condition of the same cement recipe and fineness of finished products, the output of No. 1 mill was increased by 38%, and the power consumption of the system was reduced by 3 kW?h/t. The output of No.2 mill is 22%, and the power consumption of the system is reduced by 2.6 kW?h/t.