The invention provides a large-amplitude vertical-torsional coupled free vibration device, which belongs to the technical field of vertical-torsional coupled free vibration device for wind tunnel test. The gear blocks are consolidated at both ends of the beam. The screws, beam, and the gear blocks are fixed on the model, and they can fulfil the vertical-torsional coupled free vibration. The toothed plate is attached to the sliding block that iteratively moving along the vertical guide rail which is fixed to the ground. The vertical springs attached to the sliding blocks provide both vertical and torsional linear stiffness for the suspension vibration system. The springs only have vertical linear tensile deformations without any lateral tilt, which ensures the linear vertical and torsional stiffness of the model, and the lateral freedom is effectively restrained. This device can achieve the large-amplitude vertical-torsional coupled free vibration of the model, and the deficiency of the traditional device where springs are apparently tilted and the inefficacy of linear stiffness can be avoided. The lateral vibration is restrained, and it is applicable to large-amplitude vertical-torsional coupled free vibrations.