The invention discloses a multifunctional automatic vacuum oven for lithium batteries. The multifunctional automatic vacuum oven comprises an oven thermally-insulating outer shell, a vacuum heating inner chamber, a vacuum pump exhaust system, an automatic heating control system and an automatic rotating mechanism. The vacuum heating inner chamber comprises an inner chamber body. Rotary driving motors are mounted on the inner wall of the inner chamber body. A rotating main shaft is connected between the rotary driving motors in a sleeved manner. A rotary baking bracket is connected to the rotating main shaft in a sleeving manner. A vacuum seal valve is inlaid into the top of the vacuum heating inner chamber. The automatic heating control system comprises a microwave magnetron and a voltagechanger. The control end of the voltage changer is connected with an automatic adjustment module. A power regulator is connected between the signal output end of the automatic adjustment module and the power control end of the microwave magnetron. The multifunctional automatic vacuum oven has the functions of microwave heating and drying; in addition, vacuum environment protection can be achieved;damage to the lithium batteries is greatly reduced while the drying efficiency is effectively improved; and a drying device can be dismounted and moved conveniently, and flexibility is high.