The invention discloses a novel shitake mushroom dreg comprehensive utilization method. The method adopts a formula which comprises 60 to 70 percent of shitake mushroom dregs, 25 to 30 percent of cottonseed hull or corncob, 5 to 10 percent of bran, 0.1 percent of dipotassium phosphate, 0.2 percent of plaster and 0.2 percent of quicklime, wherein the shitake mushroom dregs are used as the main material and a small amount of the cottonseed hull or corncob is added into the main material; and the proper amount of bran, dipotassium phosphate, plaster and quicklime are added as auxiliary materials. The method comprises the following steps of: completely and uniformly blending the mixed materials, adjusting the moisture content to 60 to 63 percent and regulating pH to about 6.5, filling the mixed materials into bags, performing sterilization, cooling the sterilized bags, and inoculating a pleurotus ostreatus strain into the bags; culturing the pleurotus ostreatus for 35 to 40 days at the temperature of between 20 and 25 DEG C, and performing pleurotus ostreatus picking management after hyphae grow fully in the culturing bags, wherein the pleurotus ostreatus can be picked for 3 to 4 times. The method of the invention can realize the recycling of the shitake mushroom dregs, effectively reduce environmental pollution caused by the shitake mushroom dregs and reduce the production cost of the pleurotus ostreatus at the same time; the biological yield can reach about 80 percent; and the method is applicable to areas where the shitake mushroom is cultivated in sawdust bags.