Through three-dimensional nonlinear finite element analysis, the punching failure’s bearing mechanism of the independent foundation under column whose slab is the size of 0.8m×0.8m×0.3m is obtained. The transfer mechanism of the foundation is spatial strut-and-tie model, where the reinforcements located in the link ranges between each adjacent corner of the slab are represented by ties, and the concrete distributed in the link ranges from the column bottom to four corners of the slab bottom are represented by struts. The indication of punching failure is that the concrete at the two ends of the struts reaches the shear-compression failure strength, and the punching cone is punched out relative to the slab, which has distinct punching failure features. A new spatial strut-and-tie model composed of four ties and four struts is proposed on the basis of clear bearing mechanism, which provides a new idea for the calculation of the punching bearing capacity of the independent foundation under column.