Abstract: Aiming at the serious erosion wear on components of coal water slurry valve with high pressure during coal gasification, based on the fluid physical parameters, operation conditions and three-dimensional flow structure of coal water slurry valve, the mathematical model and calculation method are constructed to describe the process of flashing, particles movement and erosion wear. Then the numerical simulation on the erosion wear in the valve is carried out. The results show that severe erosion wear locate on the top of valve spool and the entrance of valve bushing. Among them, the maximum erosion rate occurs on the top surface of valve spool. The numerical results agree well with the actual failure instance, thus the accuracy of calculation model and method is verified. The research results can provide the reference for failure analysis and structural optimization of the similar valves.