Corrosion and erosion are the main factors of pipes failure. Erosion wear characteristics of elbow pipe with corrosion defect are investigated in this paper. Initially, the erosion result of nondefect elbow pipe is calculated and compared to elbow pipe with corrosion defect. An elliptical erosion area with a V-shaped dent occurs at the extrados due to the particles' impact. The uniform corrosion defects change the structure of the pipe's inner surface. Therefore, the defect areas are more prone to be impacted by particles and then more severe erosion occurs. The maximum erosion rates of corrosion defect and noncorrosion area synchronously reach the maximum value as the corrosion defect located at 55 deg. The larger the particle mass flow rate is, the more severe the elbow pipe erosion is. As the flow rate increases, erosion rates of corrosion area and noncorrosion area increase, while the maximum erosion rate of corrosion area occurs at 55 deg. Structural parameters of corrosion defects affect the erosion. As the distance between two corrosion defects increases, the maximum erosion rate of lower corrosion defect increases. Considering the location, structure, and number of corrosion defect, a larger corrosion defect located in the middle of extrados has a worse effect on elbow pipe safety.