Abstract: Aliphatic diol HO―(CH₂)₆―S―S―(CH₂)₆―OH containing disulfide bond (DSU) was synthesized by the nucleophilic substitution reaction of halohydrocarbon, which was introduced into polyurethane molecules in the form of hard segment. A series of polyurethane composites modified by disulfide bond were prepared by using methylene diphenyl diisocyanate (MDI), dopamine modified castor oil and DSU as raw materials, and their structures and properties were optimized. The chemical structure of DSU was characterized by ¹H-NMR, and the influence of DSU amount on polyurethane was investigated, including the compressive mechanical properties, water contact angle, microstructure and bone bonding strength. The main conclusions include that the compressive properties and hydrophobicity of polyurethane composites increased with the increase of DSU dosage, and the bone adhesion strength increased first and then decreased. As m (DSU)∶m (DACO)=10% , the composites presented the best comprehensive properties with the bone adhesion strength of 0.97 MPa in the buffer solution and 0.49 MPa in rabbit blood, compression strength of 7.0 MPa, compression modulus of 41.3 MPa and average bubble size of 150 μm. In vitro culture experiments of rat bone marrow mesenchymal stem cells showed that the polyurethane composites had excellent cytocompatibility. The cell staining results by Calcein-AM showed that the porous structure of the material was conducive to cell proliferation and adhesion, which was in favour of fracture healing and reconstruction. This new material prepared in this work is expected to be used in the field of medical bone adhesives.