Bottle cap

The utility model provides a bottle cap, includes lid and lower lid, is being equipped with the connecting portion that can buckle on the lid down, and the one end and the upper cover body coupling of connecting portion are equipped with the open slot at lid down, and the cavity of open slot and lower lid communicates with each other, is equipped with thin wall spare in the open slot. Bottle cap's lower lid and bottle are connected, and the bottleneck of bottle is equipped with protruding threads, and at the in -process that the lower lid with bottle cap took out from the bottle, protruding threads can act on the thin wall spare in the open slot, make thin wall spare structure receive destruction, and bottle cap opens back thin wall spare structure can not recover the original shape, has disposable anti -fake function.