The desulfurization and denitrification tower is the core equipment of the carbon-based catalytic multi-pollutant collaborative control technology. Its design strength ensures the pollutant removal effect and stable operation of the system. This paper used ANSYS finite element analysis software to establish a three-dimensional model of the tower and divided it into high-precision grids. Combined with actual load analysis, calculation and working condition combination, the deformation and stress distribution nephogram of the tower and the membrane stress and bending stress of each component were calculated. The strength check and stress assessment were carried out. When the calculation error is ignored, the overall design strength of the tower meets the requirements, but the stress of the local reinforced beams exceeds the limit. It is recommended to replace the steel with a higher allowable stress value.