The utility model discloses a that reserves cavity, thickening of bight entity prevents falling cell -phone protective sheath that takes precautions against earthquakes, this cell -phone protective sheath includes protection sleeve body, protection sleeve body integrated into one piece, protection sleeve body's corner sets become the arc angle, the cover body of this arc angle is the thickening cover body, the bottom of cambered surface is provided with the arc groove in it, the cell -phone cover behind the protective sheath, vacuole formation between arc groove and the cell -phone bight, arc-face groove has been offered once more to the bottom surface of the interior cambered surface of protection sleeve body's the lateral part cover body, this arc -face groove and arc groove intercommunication, cell -phone cover behind the protective sheath, vacuole formation between to the side of arc -face groove and the cell -phone. The utility model discloses the cavity is all left to cell -phone protective sheath bight and lateral part and cell -phone side, and this cavity has the function of preventing falling, take precautions against earthquakes, break after avoiding the cell -phone to drop, protection sleeve body's the external side of lateral part cover downside, with protection sleeve body bottom surface corner, be provided with radial arc -face groove, push cell -phone protectivehousing lateral part or bight aside easily, take out the cell -phone.