Abstract: An experimental study consisting was conducted to evaluate the shear bearing capacity of hairpin slab joints used in new-type precast concrete floor diaphragm． Crack and failure mode，load-displacement relationship curves， energy dissipation capacity of the test specimens was evaluated． And the test results reviewed that the hysteretic curves of hairpin connection was full，which showed good energy dissipation and seismic performance． The in-plane shear bearing capacity of the hairpin slab joint which consisted of couple arranged hairpin mechanic connectors in both side of the slab can be predicted in superposition method based on stud-and-tie mode theory．