The present invention is a cover for a mushroom cultivation bag, comprising a body and a gas permeable sheet, the body having a positioning portion, a gas permeable portion and a consistent hole, the gas permeable portion having a side wall and a bottom wall, the side wall being connected to the positioning portion and piercing There are a plurality of vent holes, and each of the vent holes communicates with the inside of the space bag and the through hole, and the bottom wall is provided with a medium pressed against the space bag, and the gas permeable sheet is glued to the positioning portion and closes the through hole Since the gas permeable sheet is made of a gas permeable material, the air in the space bag can pass through the venting holes, the through holes and the gas permeable sheet to exchange the outside air, thereby maintaining the air permeability of the space bag.本新型為一種菌菇培植包的封蓋，包含有一本體及一透氣片，本體具有一定位部、一透氣部以及一貫孔，該透氣部具有側壁及底壁，側壁連接於定位部且穿設有複數個透氣孔，且各該透氣孔與太空包內部及該貫孔連通，而底壁則供以壓抵於太空包的培養基上，透氣片則是膠合於該定位部並封閉該貫孔，由於該透氣片是以能夠透氣的材質製成，太空包內的空氣能夠經過各該透氣孔、該貫孔及該透氣片，以對外部空氣進行交換，進而保持太空包的透氣性。
