Abstract: In order to ensure the safety of water supply along the water transmission line from Yangtze River to Huaihe River, based on Mike21 model, COD, ammonia nitrogen, total nitrogen and total phosphorus were taken as characteristic indicators, the current water quality analysis and scenario simulation prediction analysis of Wabu Lake were carried out. The simulation results showed that under the scenario of the full implementation of the pollution control project of the river diversion to Huaihe River project in the future, the overall water quality of Wabu Lake area would be significantly improved in 2025, and all indicators would stably meet the class Ⅲ standard of surface water, which provided guarantee for water transmission safety.