Duckweed is an important plant for wastewater remediation and a promising alternative protein source for animal feed. This study aims to evaluate the biomass, protein accumulation, and wastewater purification capacity of duckweed under controlled cultivation conditions. Using pig farm biogas slurry as a nutrient source, this study analyzes the purification ability of duckweed at different slurry concentrations (2%, 4%, 6%, 8%, 10%) on chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and ammonia nitrogen (NH