Fusing device for spaceflight

The invention provides a fusing device for spaceflight, which comprises a base, a guide rod, a sliding block, a heat knife, an elastic component and a top cover, the sliding block is arranged in a groove body of the base, the guide rod penetrates through a sliding block through hole of the sliding block, the elastic component is sleeved on the guide rod, the elastic component can push the sliding block to move along the guide rod, two ends of the guide rod are fixed with the base, and the heat knife is arranged on the top cover. An embedding groove is formed in the side, away from the elastic component, of the sliding block, the hot knife is embedded in the embedding groove, the surface of the hot knife protrudes out of the surface of the sliding block, the top cover is buckled on the groove body, the hot melting line penetrates through a top cover center hole of the top cover, the groove body and a center hole of the base which are communicated, and the hot knife abuts against the hot melting line under the