Abstract: Horizontal spray tower technology is a new flue gas desulfurization system technology that was developed at the University of Science and Technology Beijing, Center for the Environment, overcoming the shortcomings of the vertical spray tower with regard to high desulfurization efficiency, small pressure loss, low operation cost, and easy maintenance, among others. However, the actual project still requires further improvement. In order to study the influence of the layout pattern of different spray on the internal flow field of the horizontal spray tower, the physical model of the horizontal spray tower was built, the grid was divided by Icem software, the Fluent software was used to simulate the numerical simulation. K-epsilon turbulence and stochastic models were selected for numerical simulation. The simulation results, obtained by the SIMPLE algorithm, show that the double spray sets the spray cone angle at 90°, the upper spray height is at 0.9 m from the top, the lower part of the spraying height is at 2.4 m from the top layer, the spray distance is 1.5 m, the desulfurization tower effectively reduces the pressure loss and energy consumption, the absorption area of the flue gas flow rate is uniform, and the gas-liquid contact frequency increases. The gas temperature is suitable for a gas-liquid reaction. The overall increase in the efficiency of flue gas desulphurization provides guidance for the design of practical engineering applications.