Abstract: The application of FHUDS-2 catalyst in hydrotreating unit processing coker gas oil mixed with coker naphtha at Lanzhou Petrochemical Company was introduced. The operation results showed that the hydrodesulphurization activity of FHUDS-2 catalyst was better than that of the imported catalyst in the base case. Using FHUDS-2 catalyst under the operation conditions of a processing capacity of 75 t/h, reactor inlet temperature of 300 ℃, a purity of recycle hydrogen over 86% and coker naphtha of the mixed feed in the range of 10%—20%, the sulfur removal rate reached 92%—95%. The sulfur mass fraction of the treated diesel fuel was less than 0.035%, which could meet the requirement of National Emission Standard III for automobile diesel fuels.