The phosphogypsum-based cementitious material is prepared by original untreated phosphogypsum. The mechanical property of the prepared material was tested and effects of quicklime, cement/lfy ash ratio and curing regimes on the mechanical property were investigated. The results showed that the optimal ratio of the system is 60%for phosphogypsum, mass ratio of cement and lfy ash is 1∶4, 4%quicklime,water feed ratio 0.25 and water-reducer 0.2%. Compressive strength and rupture strength declined sharply when the amount of phosphogypsum more than 60%in PFQC system. Steam curing 10 h under 75℃has a greater inlfuence on the compressive strength for the base that 28 d compressive strength is 30.1 MPa, water absorption is 8.5%, softening coefifcient is 0.82.