This paper presents one syntactic foam with excellent mechanical properties and prominent hydrostatic pressure performance for 11000 meters deep-sea. The properties of the syntactic foam are studied on the basis of relevant standards. The compressive strength, compressive modulus and shear strength of syntactic foams are about 100MPa, 1300MPa and 40MPa separately in atmosphere environment. The water absorption of the material is less than 1percent in the 110MPa hydrostatic pressure for 8h, and the appearance maintains intact in the 140MPa hydrostatic pressure when the density of the syntactic foam is between 0.670 to 0.688g/cm3.