The utility model discloses a double-channel water-cooling rotating shaft type vacuum dynamic sealing device which comprises a dynamic rotating shaft and an elastic stopping ring. The dynamic rotating shaft is in transmission connection with a sealing seat through bearings, bearing glands which are connected through hex head screws are arranged outside the bearings, a hole is arranged on the center of the dynamic rotating shaft in drilling mode, and a water guide pipe is inserted into the central hole of the dynamic rotating shaft. An opening end of the central hole is closed by a water guide hole complement core. A water inlet mouth is communicated with the interior of the water guide pipe, the tail end of the water guide pipe is communicated with an interlayer which is arranged between the water guide pipe and the interior of the central hole of the dynamic rotating shaft, and finally is communicated with a water outlet mouth, and the water inlet mouth and the water outlet mouth are arranged on a water-cooling sealing seat. The double-channel water-cooling rotating shaft type vacuum dynamic sealing device has the advantages that a cooling water channel is formed by the dynamic rotating shaft and the water guide pipe which is inserted in the dynamic rotating shaft, and the cooling water channel does fully cool for the dynamic rotating shaft, the bearings, framework oil sea, filled vacuum grease materials and the like, wherein the dynamic rotating shaft, the bearings, the framework oil sea, the filled vacuum grease materials and the like avoid being influenced by high temperature baking.