Abstract: In order to ensure the efficient and stable operation of the desulphurization system, the process flow and reaction principle of the absorption tower system at Pinghai Power Plant are described, and the adverse effects of high dust concentration on the desulphurization system are analyzed. An optimized gypsum primary dehydration system is proposed to solve the contradiction between wastewater discharge and gypsum production, and to improve the absorber slurry quality and ensure the gypsum quality by adding a new line to the wastewater treatment system. The practice shows that this method is feasible.