The utility model discloses a precast concrete decking and girder steel shear connector, including cant chisei and sleeve, the surface of cant chisei is provided with the sleeve, and the cant chisei root passes through screw thread and girder steel roof?connection, the sleeve is frustum type structure, telescopic frustum type structure comprises the semi -circular frustum that two symmetry of each other set up, and it is fixed mutually that modes such as buckle or screw are passed through to two balanced semi -circular frustum structure of each other. Compare the cant chisei connecting piece, the utility model discloses the initial rigidity of joint construction is less, can effectively improve the stress of cant chisei, and under horizontal action of shear force, the stress of cant chisei is followed the direction of height and is tend to evenly distributed, avoids near cant chisei compressive region concrete to be crushed simultaneously, increases substantially the bearing capacity that shears of cant chisei connecting piece.