Drilling riser system is a critical component of marine oil drilling, and buoyancy module is essential for deep-sea drilling riser system. In this paper, three phase epoxy buoyancy materials filled with carbon fiber reinforced hollow macrospheres and hollow glass microspheres was prepared by vacuum pour molding. Strength analysis has been conducted on the buoyancy modules with different load conditions by using ANSYS. The results show that the density of buoyancy material is 500 kg/m³ and the compressive strength is 60 MPa. The maximum deformation of buoyancy modules occurs in the free end with a value of 4.08 mm. The maximum stress occurs on the structure adjacent to riser with a value of 50.02 MPa, which makes the prepared buoyancy modules meet the drilling requirements of 3 000 m water depth.