To save water in mandarin orange canning industry,a water reuse system for mandarin orange canning factory was designed in 50t/h in production scale.The discharged water from mesh belt was collected in pool,separated operation of chlorination,filtering by active carbon and sterilization by ultraviolet,and then reused for the grader、the process of segmenting,transportation,and washing after alkaline solution treatment.The water quality had been monitored during the water reuse system,it is showed that the reused water quality was improved by the system and the main physical-chemical properties and sensory index conformed to the requirements of relative national standard GB5749 except COD.The reused water contained about 0.4mg/kg residues chlorine and 10ug/ml pectin.The Total bacterial count ≤10 cfu/ml and no E.coliform Group was detected.Its trial running results of a season production indicated that the quality of output water met the design requirements and possessed huge development potential in mandarin orange canning industry.