The utility model belongs to the technical field of shield tunnel construction in the civil engineering industry. The utility model relates to a tunnel steel ring inner support connecting joint. The connecting joint comprises connecting plates, stiffening rib plates, base plates and high-strength bolts, the two arc-shaped steel beams of the combined steel ring inner support are in butt joint through the upper connecting plates and the lower connecting plates, round bolt holes are formed in the four corners of the two tunnel supporting connecting plates, and the two arc-shaped steel beams are connected in a fastened mode through the high-strength bolts, the base plates and the connecting plates. When the connecting plates are connected with the arc-shaped steel beams, stiffening rib platesare additionally arranged on the sides of the arc-shaped steel beams to resist lateral deformation of the arc-shaped steel beams; the arc-shaped steel beam butt joint device is simple in structure, convenient to install and splice and firm in connection, the arc-shaped steel beam butt joint operation efficiency can be improved, the technical problem that the axis is prone to deviating during arc-shaped steel beam splicing is solved, meanwhile, extrusion force borne by the arc-shaped steel beams can be effectively solved, and steel ring deformation is effectively prevented.