This paper presents an experimental investigation on the load transition mechanism of the joint surface , and the effects of shearing stud and bar-planted placements on structural capacity for the steel-concrete composite strengthening structure with coated steel plate. Six groups of steel-concrete composite specimens with various deployments of shearing stud and bar-planted are carried out. The influences of the arrangement interval of shearing stud and bar-planted on the mechanical behavior and load-bearing capacity are compared; the working and damage behavior of the steel-concrete composite joint surface is studied based on the experimental data and failure modes. Results showed that compared with the steel-enveloped approach with greater rigidity of the reinforced structure, the structure is reinforced by the enveloped steel plate with greater rigidity, and the strength of the joint surface is higher. The grouting-connected pattern of bar-planted and shearing stud cannot satisfy the correspondence deflection requirement of enveloped steel plates and inner-concrete cores due to the stricter strength requirement of the joint surface . Although the changes in number of shearing stud nearly have no effect on the structural stiffness and the ultimate capacity of the enforced components for a certain range, the premature local instability of enveloped steel plates is prevented, by which the plasticity and ductility can be fully utilized.