The invention discloses a four-point bending beam-based bituminous mixture interlaminar shear strength testing device. A first support and a third support are arranged at the bottom of a loaded I-shaped beam, the first support is hinged to a first bending beam clamp, and the third support is hinged to a third bending beam clamp; a second support and a fourth support are arranged at the top of a base, the second support is hinged to a second bending beam clamp, and the fourth support is hinged to a fourth bending beam clamp. By regulating the positions of the bending beam clamps and the supports, the four-point bending beam-based bituminous mixture interlaminar shear strength testing device can guarantee that the vertical load applied onto a test piece corresponds to the designed length of a moment arm, and due to the interaction of vertical load and hinging, the interlaminar of a test piece only bears shearing load without the influence from bending moment stress, thus facilitating reasonable explanation and analysis on the interlaminar cementation situation of bituminous pavements in a pure shearing state, and simultaneously lightening the influence of rigidity of the bending beam clamp on testing results.