In order to study the influence of sleeve section size on the mechanical performance of grouted sleeve lapping connector， 39 specimens with different sleeve thicknesses and inner diameters were tested in unaxial tension， and their failure mode， ultimate bearing capacity， ductility， reinforcement and sleeve strain were studied. The results show that the failure forms of the specimens include tensile failure and pull-out failure of reinforcements. Due to the influence of eccentric loading， the effective lap length of the specimen is about 81% of the design lap length. When the inner diameter of the sleeve is the same， within a certain thickness range， the constraint of the sleeve increases with the increase of the wall thickness， and the bearing capacity of the specimen increases. When the wall thickness of the sleeve is the same， the constraint is weak when the wall thickness is small （1.5 mm）. The larger the inner diameter （similar to the thickness of the protective layer）， the greater the bearing capacity of the specimen. When the wall thickness is greater than or equal to 2.0 mm， the constraint is enhanced， the specimen is broken under tension， and the increase of the inner diameter has little effect on the bearing capacity. In the elastic stage， the influence of sleeve wall thickness on the bond force between reinforcement and grouting material is more obvious than that of sleeve inner diameter. The longitudinal strain of the middle section of the sleeve is tensile in the early stage of loading but gradually transforms to compressive strain with the increase of load. The circumferential strain of the middle section of the sleeve is compressive in the early stage of loading but gradually changes to tensile strain with the increase of load. The formulas for calculating the ultimate bonding stress of the connector and the critical lap length of the reinforcement are put forward， which have good applicability and can be used as a reference for practical engineering.