The utility model discloses a variable-gradient slope model test device, which comprises a base, a main body box, a transverse loading device, a pile body, a vertical loading device and a displacementmeter, and is characterized in that the base is arranged at the bottom of the main body box; the pile body is arranged along the center line of the main body box in the vertical direction, a verticalloading device is arranged at the top end of the pile body, and the upper part is connected with a transverse loading device; the displacement meter comprises a displacement sensor and a receiver; the displacement sensor is arranged at the top end of the pile body; upper half side plates of two opposite surfaces of the main body box comprise a plurality of triangular splicable plate units; the device can effectively simulate the side slope terrain and the pile body environment, is flexible and convenient to operate, can be recycled, and can be used for observing the deformation condition of soil and observing whether cracks are generated or not; the pile-soil environment can be simulated more truly, and the pile foundation bearing capacity and the settlement conditions of the pile top andthe pile body can be known through the transverse loading device, the vertical loading device and the displacement meter.