The utility model relates to a device for connecting prefabricated formula floating plate, floating plate including butt joint installation mutually connects into a rectangular railway roadbed, is thequad slit in the middle of the railway roadbed that two adjacent floating plate formed, and the both sides waist is the opening, floating plate's both sides face is provided with the recess, installing channel steel in the recess, it has the round hole to open on the channel -section steel, and the internally mounted of channel -section steel has the connecting piece to lock through the stay bolt. The utility model discloses compact structure, equitable, convenient operation, through adopting the powerful formula shear hinge of side, shear hinge transmission shear force can the reinforce, thetrack ride comfort is good, and the vibration isolation is effectual, has solved adjacent floating plate's installation space problem simultaneously, reduces and has solved attitude error and orientation problem.