SiO₂ aerogel was used to modify geopolymers. Influences of slag content and aerogel content on the compressive strength， dimensional stability， water loss and microstructure were analyzed to provide guidance for solving the problem of geopolymer drying shrinkage. Results show that the strength of specimens with low slag content at 28 d is greatly increased due to the water retention because of aerogel. At the slag content of 30%， the higher the aerogel content， the more significant the dimensional stability. Water loss of specimens within 7 d is much greater than the specimens after 7 d. As the aerogel content increases， water loss of specimens with lower slag content is first reduced and then increased. However， water loss of specimens with higher slag content is increased first and then decreased. When slag content is 30% and aerogel content is 8%， the microstructure of specimens is the most compact.