The invention discloses a scaffold swinging fatigue tester, which comprises a chassis, a servo motor, a reduction gearbox, a connecting flange and a counterweight assembly. The scaffold swinging fatigue tester is characterized in that the servo motor and the reduction gearbox are arranged in the chassis. The connecting flange is arranged on the reduction gearbox. The flange surface of the connecting flange is located above the chassis. The counterweight assembly is arranged on the flange surface of the connecting flange. According to the technical scheme of the invention, based on the above simple and practical structure, the servo motor drives the counterweight assembly to rotate so as to swing the tester. In this way, the swinging fatigue test on the fast-assembling scaffold made of the composite material can be realized, and non-qualified products are eliminated. Therefore, the overall body of the scaffold is prevented from laterally tilting due to the swinging fatigue. Meanwhile, the permanent deformation and the cracking of the components and the parts of the scaffold are avoided. Moreover, the failure of a locking device, the blocking of connectors and the like are avoided. As a result, resulted potential safety hazards are eliminated. The incidence rate of serious accidents is lowered.