A stretchable strain sensor based on vertical graphene having a stretch ratio of more than 50% and is capable of recognizing timbre with frequency greater than f hertz, f being 100, 800 or 2500, and having a sensitivity factor greater than 100 at 50% stretch, wherein the vertical graphene comprises a bottom plane layer and a vertical layer and contains high-density reticular cracks, wherein the directions of the cracks can be transverse, vertical and oblique directions, wherein the reticular cracks divide the vertical graphene into a plurality of small blocks, and adjacent small blocks are electrically connected through the vertical layer in stretched state, the cracks widen, but still can be bridged by the vertical layer, the two sides of the cracks still remain electrically connected, the sensor remains effective, wherein average diameter range of the plane of each small block is between 5 and 20 microns.