Disclosed is a method for preparing bitter Ganoderma lucidum spore powder, and relates to the field of drugs or health care products. The method includes: removing visible impurities from Ganoderma lucidum spores, conducting ice bath and heating extraction, filtering through a microfiltration membrane, sterilizing by drying, and conducting sporoderm disruption to obtain the bitter Ganoderma lucidum spore powder. The preparation method effectively improves the content of the bitter substances in the Ganoderma lucidum spore powder by removing shriveled spores through multiple times of impurity removal and filtration in combination with the manner of conducting sporoderm disruption after extraction. Taking the total Ganoderma lucidum triterpenoids in the Ganoderma lucidum spores as a representative of the bitter substances, the content of the total Ganoderma lucidum triterpenoids can reach 5-8%. Meanwhile, the preparation method can also make the content of Ganoderma lucidum polysaccharides reaching 6-10%.