Disclosed is an edible mushroom cultivation method with reed substituting for cottonseed hull. Applied cultivation materials are composed of, by weight proportion, 48-52 of reed chips, 33-37 of corncob powder, 8-12 of wheat meal or corn meal, 2-4 of bean pulp, 0.5-1.5 of diammonium phosphate powder and 0.5-1.5 of lime powder. The method comprises the specific steps of, firstly, preparing the reed chips through crushing and fermenting processes; secondly, performing pretreatment on the corn meal or the wheat meal; thirdly, uniformly mixing the materials in a mixer, during mixing, feeding carbon dioxide into a mixing barrel; fifthly, bagging the materials; lastly, performing sterilization and inoculation. The invention also discloses a reed crushing device. The edible mushroom cultivation method with the reed substituting for the cottonseed hull has the advantage of, without the cottonseed hull as the raw materials, reducing the costs and avoiding the problems such as high pesticide residue, and during mycelial growth, being proper in nutrition, reducing contamination during edible mushroom cultivation, increasing the content of carbon dioxide in bags and being promising in mushroom bag production.