The present invention discloses a foldable breathing mask, comprising: a mask body and a breathing tube, wherein the top end of the mask body extends upwardly to form a connecting tube, and one side of the connecting tube and the corresponding side of the breathing tube are respectively provided with a hinge mechanism, such that the breathing tube is turned over downwardly to be flatly attached to the mask body or turned over upwardly to be communicated with the connecting tube, the other side of the connecting tube corresponding to the hinge mechanism is provided with an elastic hook, and the breathing tube is correspondingly provided with a hook groove or a hook opening. The foldable breathing mask has the advantages of quickness in folding and convenience in assembling.