Abstract: Different combinations of spray layers and gas-liquid two-phase parameters of the desulphurisation tower have a large impact on the desulphurisation efficiency. The analysis and study through numerical simulation can provide a theoretical basis for the design of the intelligent control system of the wet FGD tower. Firstly, according to the standard k-ε equation describing turbulence, component transport and Eulerian-dense discrete-phase multiphase flow model, the physical model of the wet FGD tower is constructed. Then, ICEM software is used to simplify the physical model and perform structured meshing. Finally, the desulphurisation process of the wet FGD tower was numerically simulated using Fluent software and SIMPLE algorithm under the set boundary conditions. Among them, the article mainly simulated the effects on the desulphurisation efficiency of the residence time of the sprayed slurry particles under different spray layer heights, the distribution of the sulphur dioxide content in the tower, and the parameters such as the amount of slurry spray, the initial velocity of the slurry spray, the velocity of the inlet flue gas and the sulphur dioxide concentration of the inlet flue gas. Simulation results show that: the height of the spray layer is directly proportional to the contact time between the sprayed slurry particles and the flue gas; the initial velocity of the slurry spray has a relatively small impact on the desulphurisation efficiency; the desulphurisation efficiency can be significantly improved by optimizing the combination of the spray layer, reasonably adjusting the amount of the slurry spray, and controlling the inlet flue gas velocity and concentration and other parameters.