The invention discloses a device for testing the mechanical properties of a pile-soil contact surface. The device is composed of a sealed pressure chamber, a hollow cylindrical soil sample, a solid cylindrical concrete pile sample and the like. The pile sample is prefabricated, and its diameter is equal to the internal diameter of the hollow cylindrical soil sample, and the two samples joint together closely. The lower end of the concrete pile sample is disposed on a pedestal through a spring assembly, and the upper end is connected to a stress loading system through a dowel bar, which is provided with a stress sensor and a displacement sensor I. The outside of the concrete pile sample is the hollow cylindrical soil sample. Filter paper and permeable stones are disposed at the lower end of the soil sample, and the lower end is positioned on the pedestal, while the upper end of the soil sample is provided with filter paper, permeable stones, a top cover and a displacement sensor II in order. During test, a confining pressure is exerted first for consolidating, and then a static (dynamic) load is exerted on the pile sample for measuring the axial deformation, pore water stress and the like of the pile and the soil. The device provided in the invention has a simple structure, is easy to realize, and can be used to measure the mechanical properties of a pile-soil contact surface under the action of a static (dynamic) load.