The invention relates to an edge clamping device of a cloth rolling machine. The device comprises a horizontal track, two edge clamps, screw rods and driving devices, wherein the horizontal track is arranged on a rack of the cloth rolling machine; the two edge clamps are arranged on the horizontal track; the screw rods are used for pushing the edge clamps to move on the horizontal track; the driving devices drive the screw rods to rotate; each edge clamp comprises an edge clamping frame, two edge clamping rollers, a positioning device and an adjusting device; the edge clamping frame is sleeved on the horizontal track; the edge clamping rollers are arranged on the edge clamping frame and can rotate around own axes; and the adjusting device is used for adjusting the space between the two edge clamping rollers. The device has the following advantages: according to the width of the cloth, the screw rods are adopted to push the two edge clamps to form a certain tension in the width direction of the cloth, so that the cloth is flatter; and the device has a simple structure and is convenient to operate.