This　paper　presents　a　design　of　a　prefabricated　structure　for　an　underground　cylindrical　garage.　The　performance　of　this　structure　and　the　node　connections　in　terms　of　lateral　stiffness　is　investigated,　which　is　critical　to　the　safety　of　the　excavation　process.　Analytical　solutions　of　the　lateral　stiffness　of　the　prefabricated　structure　are　derived　considering　compatible　displacement.　A　3D　model　of　the　prefabricated　structure　is　developed　and　used　in　the　numerical　simulation　to　verify　the　theoretical　model.　As　the　key　factor　of　the　lateral　stiffness　of　the　prefabricated　structure,　the　lateral　stiffness　of　the　node　is　also　obtained　via　laboratory　testing.　Three　connection　nodes　are　fabricated　according　to　the　design　and　are　tested　in　the　laboratory.　The　influence　of　the　cross-sectional　area　of　the　connection　beam　and　the　thickness　of　the　column　base　on　the　lateral　stiffness　of　the　connection　node　is　also　investigated　in　the　laboratory　test.