Solid Buoyancy Materials with different content of hollow glass microspheres was synthesized by molded forming, withbisphenolepoxy resin E51 as bulk material, methyl tetrahydrophthalic anhydride as the curing agent, hollow glass microspheres named K25 as lightweight filler. The influence of the content of glass microsphereson density, uniaxial compressive strength and resistance to hydrostatic pressure of solid buoyancy materialwas studied. The results showed that the introduction of microspheres with lower density could reduce the density of solid buoyancymaterial effectively. With the increasing of hollow glass microsphere content, the deviation between theoretical density and actual density increased, and the uniaxial compressive strength and resistance to hydrostatic pressure of solid buoyancy material decreased. Especially, when the content of hollow glass microsphere exceed 18%, the decrease amplitude of the uniaxial compressive strength and resistance to hydrostatic pressure increased.