The utility model relates to a small-diameter sand blower with a large sand quantity for casing-damaged well fracture. An inner hole in the lower end of an upper joint of the sand blower is connected with a center tube, the outer wall of the upper joint of the sand blower is connected with an adjusting ring, a spring and a valve sequentially sleeve the outer wall of the center tube blow the adjusting ring, the lower end of the valve is seated at an upper opening of a valve seat, a ring cavity is formed between the valve seat and the center tube, a sand outlet hole is formed in the wall of the center tube below the valve and communicated with the ring cavity, the lower end of the valve seat is connected with a lower joint through a fixing pin, a sliding sleeve sleeves the center tube and is fixed by a shear pin on the upper portion of the sand outlet hole, the lower end of the sliding sleeve is connected with a guide head, and a clamp spring is mounted between the upper end face of the guide head and the sliding sleeve. A fracturing string comprising the sand blower can realize four-layer immovable string fracture, abrasion of a tool caused by sand-carrying fluids is decreased by increasing the area of a fluid outlet and reducing the flow speed of the sand-carrying fluids, and the requirement of the small-diameter sand blower for increase of sand fracture is met.