The invention provides a vacuum dehumidification and drying device. The vacuum dehumidification and drying device comprises a refrigerating compressed unit and a refrigerating agent return heater connected with the refrigerating compressed unit, a high pressure air inlet of the refrigerating compressed unit is connected with a gas-fluid separator, and a high pressure air exhaust port of the refrigerating compressed unit is connected with an oil separator I. A heating tank is connected with a branch pipeline between the oil separator I and a valve IV in series, the heating tank is connected with a condensing fluid reservoir 1, the refrigerating agent return heater is connected with a freeze-dried warehouse, and the freeze-dried warehouse is connected with the gas-fluid separator. The vacuumdehumidification and drying device is reasonable and simple in structural connection and simple and convenient to operate and maintain, valves are arranged at all joints, the controllability of the device is improved, the whole structure is more smooth in dredging, the drying efficiency is high, and the energy utilization rate is high.