Abstract: Solid buoyancy material has been successfully synthesized by packing alicyclic epoxy resin E-4221 with low density hollow glass microspheres. The curing process about the epoxy resin E-4221 system and the effect of resin ingredient on the strength of solid buoyancy material were investigated. The compression strength of cured resin product was in the range of 100~150 MPa. The effect of resin ingredient and the content of HGMS on the performance of the final composites were analyzed. Solid buoyancy material was prepared with a compressive strength of 40~70 MPa,a density of 0.5~0.7 g/cm³,a water absorption rate that lower than 0.2% by optimizing the influencing conditions. The fracture surface of solid buoyancy material was briefly discussed.