To use phosphorus gypsum as filling aggregate to be filled in underground minedout area is a new way to make a comprehensive use of phosphorus gypsum.Cemented filling with phosphorus gypsum from Kaiyang Phosphorus Group Co,Ltd not only reduced storage of phosphorus gypsum on ground surface in mining area,but also provided a condition for pillars recovery.A detail description of cemented phosphorus gypsum filling system and its process in Kaiyang Phosphorus Group Co,Ltd is made.