Based on an actual project of a suspen-dome steel roof under construction, the constraint performance of cable-strut joint of a suspen-dome is studied precisely. Experiments of a full-scale cable-strut joint are conducted on and both the slipping performance and the failure mode of the joint are obtained. The concept of slipping force density is proposed to describe the slipping performance of the joint. The static friction factor is also gained in the test and the test values are compared with analytical ones. In comparison with the smooth clamping groove, the ribbed clamping groove is proposed against the deficiency of clamping strength of the joint after the cable being tensioned. The experimental and analytical results demonstrated that 10% prestress loss occurs in seal sleeve and socket ear, so that pre-stretching is recommended as compensation. In the experiment, primary joint fails with pulling out of the cable and damage of the out layer PE. The maximum slipping force for primary joint is 150 kN with the slipping force density of 18.3 kN/mm. The measured friction factor is 0.24, which agrees well with the FEM results. The maximum slipping force for the ribbed joint is 240 kN，and the measured slipping force density is 26 kN/mm, which increase, up to 42% compared with that of primary joint. It is indicated that the ribbed damping groove can fasten the cable more efficiently, and improve the sliding-resistance performance of the cable-strut joint. The research provides references for the application of this joint.