The invention discloses a method for preparing enzyme by using lemons and galangal as main materials. The method comprises the specific steps that 1, 35-45 parts of lemons, 15-20 parts of galangal, 2-5 parts of turmeric, 8-15 parts of rhizoma zedoariae, 8-15 parts of grapefruit and 8-15 parts of musa basjoo are selected and cleaned for usage; 2, the lemons are firstly extruded to make peels broken and expose pulp, then the galangal, the turmeric, the rhizoma zedoariae, the grapefruit and the musa basjoo are cut into galangal slices, turmeric slices, rhizoma zedoariae slices, grapefruit slices and musa basjoo slices which are 0.3-2 cm in thickness, and then the materials are mixed evenly to obtain a mixture; 3, the mixture is put in a sealed container, honey and water are added for even mixing, then the mixture is put in a room, sealed fermentation is performed under room temperature condition, one time of stirring is performed every day in previous 5-7 days, later one time of stirring is performed every 7 days, the cycle is kept for one month, then sealing is performed, and fermentation continues for 6 months. The enzyme prepared by adopting the method retains the effects of original foods, is rich in probiotics and nutrition and long in shelf life and has a good taste.