The invention discloses a vacuum juicer, and belongs to the field of juicers. The vacuum juicer comprises a vacuum cover assembly, a stirring cup assembly and a main unit, wherein the vacuum cover assembly comprises a vacuum cover and a cam rotating around the vacuum cover, and a sealant is arranged on the cam； the stirring cup assembly comprises a stirring cup holder and a stirring cup, and a movable valve is arranged on the stirring cup and slides up and down to control opening and closing of a stirring cup air hole； a vacuum pump in the main unit is in sealed connection with the internal space of the vacuum cover. According to the vacuum juicer, the interior of the stirring cup can be vacuumized before and during fruit juice stirring, the stirring cup can be taken out to be carried and stored in the vacuum state for a period of time, and the phenomenon that fruit juice makes contact with air and consequentially is oxidized is avoided during this period of time.
