The invention provides a pre-tightening device of a superconducting current limiter coil. The device comprises a coil support mechanism, two fixing mechanisms and an adjusting mechanism, the two fixing mechanisms are respectively arranged at end portions of the coil support mechanism to clamp the coil support mechanism, a sliding gap is arranged between the fixing mechanisms and the coil support mechanism to adjust the position of the coil support mechanism clamped in the fixing mechanisms, and the adjusting mechanism is arranged on the coil support mechanism to drive the coil support mechanism to slide along the sliding gap so that a pre-tightening force is applied to the superconducting coil. According to the device, the sliding gap is arranged between the fixing mechanisms and the coilsupport mechanism to drive the coil support mechanism to slide along the sliding gap through adjustment of the adjusting mechanism, the coil support mechanism slides close to the superconducting coilto apply the pre-tightening force to the superconducting coil, it is ensured that the tensioning and pre-tightening stresses of the superconducting coil are in accordance with the requirement, and thecondition of loosening of the superconducting coil due to thermal expansion and cold contraction is solved.