This paper focuses on turbidity treatment technology in a Zhejiang water purification plant with a daily capacity of 80,000 tons, using Taihu Reservoir as its water source. The raw water exhibits characteristics including low annual turbidity, seasonal algal blooms, excessive manganese content, and low pH in summer, while the plant must meet stringent standards—effluent turbidity ≤ 0.3 NTU per Zhejiang’s modern water plant assessment, stricter than the national 1 NTU limit. To this end, it adopts the process: “pre-ozone contact + flocculation and sedimentation + V-type sand filtration + ozone contact + granular activated carbon adsorption + disinfection”. Aiming at flaws of traditional flap filters (e.g., increased head loss from embedded pipes, no manholes for maintenance, large footprint, algal growth), improvements were made: optimizing layout, adding manholes, adjusting overflow design, and adopting enclosed structures. The improved filters use coal-based activated carbon (8 × 30 mesh, thickness 2200 mm) and follow a three-stage backwash (air, air–water, water). Since commissioning in 2021, effluent turbidity (monitored Apr 2023–Mar 2024) has consistently outperformed standards, verifying the technology’s effectiveness in turbidity control.