The invention discloses a leakage-proof type vacuum electron beam melting device which comprises a vacuum chamber and a welding line-free water cooling crucible, wherein the welding line-free water cooling crucible comprises a crucible body and a flange plate; a mounting hole is formed in the vacuum chamber; and the welding line-free water cooling crucible is fixedly arranged at the mounting hole through the flange plate. According to the leakage-proof type vacuum electron beam melting device disclosed by the invention, the water cooling crucible combined with a heat source and a vacuum container is applied to a vacuum metal melting and purifying technology, so that the safety and the reliability are improved; particularly for an installation type mechanism, a water inlet and a water outlet are formed in the outer side of the vacuum chamber, and no welding lines and no machining surfaces are formed inside the vacuum chamber; and therefore, in case of water leakage, leaking water flows out of the vacuum chamber, and the safety is guaranteed.