For the leakage of high pressure air cooler tubes caused by corrosion, relationship between hydrodynamic factors and erosion-corrosion of high pressure air cooler tubes in the hydrocracking unit of a petrochemical corporation was discussed. Accelerating effect of hydrodynamic factors such as turbulence intensity and shear stress acting on inner wall of air cooler tubes on corrosion were quantitatively investigated by a weight loss test method. The position badly destroyed by erosion-corrosion was found. Erosion-corrosion rate of high pressure air cooler tubes was predicted according to experimental data and CFD simulation results. 