Sealing mechanism and heat supply network water replenishing device

The utility model relates to the technical field of heat supply network water replenishing, and discloses a sealing mechanism and a heat supply network water replenishing device, comprising a butt joint module, a first main pipeline and a second main pipeline which are symmetrically assembled, a sealing assembly arranged in the first main pipeline and the second main pipeline, and a pressing assembly arranged in the second main pipeline, and the sealing assembly is in transmission connection with the pressing assembly. When the sealing mechanism, the heat supply network water supplementing device and the pipeline are assembled in a butt joint mode, the first annular sealing block is extruded in the second annular sealing block, even if the pipeline vibrates due to passing of water flow, the sealing performance of the connecting position of the pipeline can still be kept, the sealing use requirement during butt joint of the pipeline is met, drainage heat is recycled, and the service life of the pipeline is pro