The invention discloses a preset-fracture-surface support pile test device capable of simulating different bending strengths, and the preset-fracture-surface support pile test device is used for simulating a continuous damage process of a foundation pit support pile. The preset-fracture-surface support pile test device comprises a prefabricated broken pile, a gasket, a nut, holed nylon bolts, a hinge fastener, a hinge and a steel wire rope, wherein the middle part of the prefabricated broken pile is divided into an upper half pile and a lower half pile through a preset pile fracture surface; the upper half pile and the lower half pile, which are positioned inside a foundation pit, are connected through the hinge fastener and the hinge; the holed nylon bolts are separately mounted on the upper half pile and the lower half pile outside the foundation pit; and the steel wire rope passes through bolt holes of the holed nylon bolts and is fixed through the gasket and the nut. At a foundation pit excavation stage, the preset-fracture-surface support pile can normally work as a common support pile, and a continuous damage process of the foundation pit can be simulated after the preset-fracture-surface support pile is fractured.