Vacuum annealing furnace with high heat preservation performance

The utility model discloses a high heat preservation vacuum annealing furnace, which belongs to the field of vacuum annealing furnaces and comprises a vacuum annealing furnace body, a sealing door mounted at the front end of the vacuum annealing furnace body, a sealing block structure mounted on the inner side of the sealing door, a sealing frame structure sleeved on the sealing block structure, and four limiting structures symmetrically mounted on the sealing frame structure. The limiting structure comprises a mounting rod, an anti-falling plate and a sealing spring, the mounting rod is sleeved with the sealing spring, the anti-falling plate is mounted at the rear end of the mounting rod, a base is mounted at the lower end of the vacuum annealing furnace body, and a heat preservation layer structure is mounted in the vacuum annealing furnace body. The gap of the contact portion of the sealing block structure and the heat preservation layer structure can be sealed, so that even if the contact portion of the s