The author prepared specimen of glass fiber-hollow glass microsphere/epoxy syntactic foam material. We have obtained the load-displacement curves by three point bending test,studied the influence of glass fiber content on the bending strength and bending elastic modulus. Through soaking test,we measured the curves of moisture rate of the specimen in H,2,SO,4, and Na OH solution over time. Through the scanning electron microscopy images,we analyzed the effect of acid-base corrosion on the bending properties. The research results showed that when the glass fiber quality ratio is 10%,the bending strength of the composite reached the maximum value,rising by 27% than the specimen without glass fiber. When added more fiber,its strength is gradually reduced. Acid-base soaking corrosion greatly reduces the bending strength of syntactic foam material. The direct reason is that acid-base solution will corrode the interface of glass fiber and epoxy matrix. It also will corrode epoxy matrix.