The structure of coke burning gas and coke particle separator in the ethylene plant at PetroChina Dushanzi Petrochemical Company is cyclone separator. With simple structure, this separator can withstand high temperature and pressure and has good application effect in separating coke particles from coke burning gas of cracking furnace. However, the wear of the inner wall of the separator has become the primary problem seriously restricting its operation cycle. After disassembling the coke burning gas and coke particle separator, it was found that its inner wall was seriously worn and the scouring thinning was local. Aiming at the wear problem of the inner wall of separator, this paper uses the research methods of theoretical analysis and numerical simulation to analyze the wear of inner wall of separator caused by gas-solid two-phase flow, and puts forward some improvement measures.