Disadvantages of the lap-spliced rebar connection between SC composite wall and RC foundation include long lap-splicing length, complicated construction, rebar congestion, and difficulty in maintaining vertical straightness. In order to solve the listed limitations, an innovative connection was proposed which used steel tube instead of rebars to optimize the structural behavior of the wall, and to improve construction efficiency. This paper conducted axial tensile tests on five connections and the effects of diameter-to-thickness ratio, number of tie bar, and steel ratio on the axial tensile behavior, crack distribution, axial tensile strength, and tensile stiffness were studied. The test results showed that the core concrete exhibited bottom diagonal cracks, middle diagonal cracks, and upper splitting cracks. Increasing the diameter-to-thickness ratio of the tube was beneficial for improving the compatibility between steel and concrete, thereby increasing the axial tensile strength and tensile stiffness. Tie bars were able to mitigate the splitting cracks, maintain integrity of the specimen, reduce the eccentricity, and improve axial tensile performance. The distribution of deformation during axial tension was uneven, showing a pattern that the most deformation accumulated at the upper and lower ends, while the deformation at the middle was small.