A preparation method of bitter Ganoderma lucidum spore powder, the prepared bitter Ganoderma lucidum spore powder, and a drug or health care product thereof. The preparation method comprises removing impurities, subjecting to an ice bath, performing heating extraction with water, filtering by a millipore filter, performing dry sterilization, and performing wall-breaking. The method can effectively increase the content of a bitter substance in the Ganoderma lucidum spore powder, and the content of total triterpenes of Ganoderma lucidum can reach 5-8%. The method can also increase the content of Ganoderma lucidum polysaccharides to 6-10%.