To fulfill the requirements for the assembly of building structures， this paper proposes a new type of socketed column-column joints， which uses internal and external sleeves as the splicing members of the upper and lower steel tube columns and is assembled only through high-strength bolts. To study its load-bearing performance under bending-shear action， three specimens were designed and studied by static tests. The load transfer mechanism， failure mode， ultimate bearing capacity， and strain development of the joints were obtained. The finite element models were established， and based on verification of the accuracy of these models， a parametric analysis of the joints was carried out. The effects of the sleeve grouting， the inner sleeve thickness， and the joint length on the ultimate bearing capacity were analyzed. The results show that the inner sleeve near the plate to the first vertical bolt is the key area for load transmission in the joint domain. The sleeve grouting and joint length reduction can retard the joint strain development， but the influence is limited. When the length of the joint and the relative bending stiffness of the inner and outer sleeves are unchanged， sleeve grouting can make the connection force performance better， and the ultimate bearing capacity is increased by 19.3%. When other parameters are unchanged， the greater the length of the node， the greater the level-hold effect. The ultimate bearing capacity is increased by 15.1% as the length of the joint is increased from 300 mm to 600 mm. The greater the thickness of the inner sleeve， the higher the load-bearing capacity safety reserve of the section. The ultimate bearing capacity is increased by 31.4% as the inner sleeve thickness is increased from 8 mm to 12 mm. Based on the finite plastic development strength criterion and level-hold effect， a formula for calculating the flexural capacity of the joints was presented. The accuracy of the calculation formula is verified by comparing experimental results with numerical predictions.