Abstract: The invention provides a preparation method of high-content Ganoderma lucidum ?-glucan and an efficient and rapid detection method thereof. The preparation method comprises ethanol-trypsin pretreatment of Ganoderma lucidum fruiting body in combination with ultrasonic-assisted alkaline hydrothermal extraction of ?-glucan from Ganoderma lucidum, and purifying ?-glucan by DEAE Sephadex A-25 Sephadex column chromatography using NAOH solution as a mobile phase, to obtain high purity (?90%) of Ganoderma lucidum ?-glucan. The detection method comprises placing the extracted ?-glucan in an autoclave and performing hydrolysis with ?-(1,3)-exo-glucanase and ?-glucosidase, and detecting and analyzing the content of the prepared ?-glucan by high pressure-acid enzymatic hydrolysis-HPLC method, using glucose as a standard. The preparation method of ?-glucan has high extraction ratio.