The invention discloses a clamping tool for the parallel testing of multiple devices of a high-low-temperature test box. The clamping tool comprises an internal fixed wiring device, an external rotating clamping tool, a thrust bearing, a worm gearing device, and a pedestal. The internal fixed wiring device is a hollow cylinder, is disposed in the external rotating clamping tool, and is coaxial with the external rotating clamping tool. The external rotating clamping tool is disposed on the pedestal. The worm gearing device comprises a gear and a worm, wherein the worm is fixed on the pedestal,and the gear is fixed at the bottom of an outer side of the external rotating clamping tool. The internal fixed wiring device comprises an upper part wiring device and a lower part with a hexagonal boss cover plate. The external rotating clamping tool comprises a main body structure, a device testing socket, and a spring probe. The clamping tool can achieve the testing of a plurality of packagingdevices through external control under the condition that the high-low-temperature test box is not opened, reduces the testing difficulty, and improves the testing efficiency.