The invention relates to a method for ultrasonic-microwave synergistic extraction of ganoderma lucidum polysaccharide. The technology includes the main steps as follows: a fruiting body of a ganoderma lucidum is dried at 50 DEG C to 60 DEG C, crushed and screened by a sieve of 20 to 60 meshes; the screened ganoderma lucidum powder is added into water so as to lead the weight ratio between material and solvent to be 1:20 to 1:50; an ultrasonic-microwave synergistic extractor is used for extraction with ultrasonic wave 50W, microwave 10W to 400W and an extraction period of 10 min to 60 min; after extraction is completed, cooling, centrifugal separation and filtering are carried out in sequence to obtain a supernatant fluid contaning ganoderma lucidum polysaccharide; the supernatant fluid iscondensed to 1/2 to 1/3 of the original volume, added with anhydrous ethanol till the content of ethanol reaching 70 percent to 85 percent in the solvent; the solvent stands till complete deposition at 4 DEG C, and then filtering and vacuum freeze-drying are carried out to obtain the ganoderma lucidum polysaccharide. The method adopts the advantages of microwave and ultrasonic wave, such as even vibration and uniform effect on each point in a sample medium, has more types of selectable extractants and larger scope of target extracts, reduces binding force between a target compound and the sample body, accelerates the process of changing into solvent phase from solid phase of the target compound and has a large amount of sample processing.