Abstract: The carbon fiber susceptors with different thicknesses of 0.2 mm, 0.3 mm and 0.5 mm were prepared based on carbon fabric and resin film by the hot moulding process, and the temperature simulation and process experiment of induction welding for carbon fiber reinforced thermoplastic composite (CFRTP) were carried out. The fusion morphologies of welded joints with carbon fiber susceptors of different thicknesses were observed. To investigate the effect of thickness of carbon fiber susceptor on the mechanical property and fracture mode of CFRTP induction welded joint, the fracture morphologies and fracture modes of welded joints with different susceptors thicknesses were analyzed after the tensile-shear test. The results show that carbon fiber susceptor enables high quality induction welding of CFRTP without introducing heterogeneous materials, but a significant inhomogeneity in temperature distribution exists at the joining interface. As the thickness of the susceptor, not only the effective joining area at the interface is reduced but also the forming effect, joining quality and mechanical property of welded joint deteriorate due to the excessive melted resin. The maximum tensile-shear strength of the welded joint is 23.77 MPa when the thickness of the susceptor is 0.2 mm. The fracture modes of welded joints include cohesive failure of the susceptor, self failure of base material, mixed failure and interface failure, which change according to the thickness of added susceptor.