This study explores the application of the QUESTOR Water Quality Model in wetland purification engineering. The multi-stage pond joint control system, with submersible aerators and biofilms, enhances water quality. QUESTOR, a comprehensive water environment model, aids simulation and decision-making in wetland decontamination projects. Focusing on ecological services, the model offers multidisciplinary decision support, assessing biodiversity and water quality. It allows interactive scenario-based simulations. Challenges in reliable simulations, especially extreme ammonium concentrations, are revealed during calibration and validation. Results show the wet-land's overall beneficial impact, with scenario analyses examining flow diversion and mechanical reaeration. The model indicates successful wetland operation, emphasizing its potential for optimizing management decisions and guiding future wetland design.