The high-cleanliness high-vacuum high-pressure heat treatment device comprises a furnace body and a furnace door,
crystal materials needing heat treatment are placed in a furnace cavity in the middle of the furnace body, and the
crystal materials in the furnace cavity are subjected to high-temperature
sintering through a first
heating furnace pipe, an aluminum
oxide furnace
pipe and a second
heating furnace pipe which are arranged on the
peripheral side of the furnace cavity. The furnace door and the furnace body are sealed through the fluororubber sealing ring, heat loss in the furnace cavity is avoided, the stainless steel
water cooling cavity is formed in the furnace door, the furnace door is cooled, the fluororubber sealing ring is prevented from being heated and deformed, and the service life of the sealing ring is prolonged; cold water is introduced into the
water cooling cavity from the water inlet to cool the furnace door, the cold water flows out from the water outlet and is recycled, continuous cooling of the furnace door is achieved, the pipe plug sewn by aluminum
oxide cloth is installed between the furnace door and the furnace cavity to block
heat transfer from the furnace cavity to the furnace door, and heat loss in the furnace cavity is further reduced.