In this paper, the particle erosion wear and electrochemical corrosion of multi-phase flow ball valve are studied numerically. Aiming at the problem of ball valve erosion and corrosion caused by dilute sulfuric acid carrying solid particles, Euler-Lagrange fluid calculation method was adopted to conduct numerical simulation of erosion and corrosion wear of gas-solid-liquid three-phase flow ball valve by using fluent software, revealing the failure mechanism of valve erosion and corrosion, and comparing the simulation results with existing literature experimental data and the erosion ball valve on the engineering site. Verify the accuracy of numerical calculation results. The analysis results show that: The flow rate in the ball valve varies in the range of 3-12 (m/s), the maximum erosion amount in the valve is 2.3×10-3 (kg/m2·s), and the maximum corrosion rate is 59.8 (mm/a). The erosion wear in the valve decreases with the increase of the opening degree. The influence of gas on the erosion of the ball valve is slight, but the complex eddy current in the valve core slows down the corrosion rate of the inner wall of the valve core. The interaction between particle erosion and electrochemical corrosion will accelerate the failure of ball valve surface coating.