Vacuum drying system

The invention discloses a vacuum drying system, and relates to the technical field of vacuum drying, the vacuum drying system comprises a vacuum dryer, the vacuum dryer comprises a feed port and a discharge port, and a heat exchange device is arranged in the vacuum dryer in a penetrating manner; a discharging hopper is arranged at the lower end of a discharging port of the vacuum dryer, heat exchange equipment is arranged in the discharging hopper and is a heat exchange pipe communicated into the discharging hopper, the heat exchange pipe is connected to a first heat pump unit, the other end of the first heat pump unit further comprises a heating end, and the heating end is communicated with a main compressor through a heat exchange pipeline. The main compressor is connected with a heat exchange equipment inlet through a pipeline; a heat exchange equipment outlet is communicated with the vacuum pump through a pipeline; after the main compressor starts to operate normally, input of starting steam can be reduce