The invention discloses a backup plate adjustable swing, which comprises a swing seat, a swing bracket, swing ropes and a backup plate, wherein the swing bracket and the swing seat are connected by virtue of the swing ropes; the swing seat and the backup plate are hinged; the swing bracket comprises a transverse pillar; a coil spring is arranged in the backup plate; a connecting rope is arranged in the coil spring; one end of the connecting rope is connected to the coil spring and the other end is connected to the backup plate; guardrail plates are arranged in the backup plate; the guardrail plates are arranged on three sides of the backup plate and mutually constitute a U-shaped structure with an opening facing the side, hinged with the swing seat, of the backup plate; a U-shaped groove,in which the guardrail plates are embedded, is additionally formed in the backup plate; sliding devices are arranged on two adjacent side faces of the backup plate; the connecting rope is contracted into the coil spring when the backup plate is turned up; and by virtue of the sliding devices, the guardrail plates are pulled out from the interior of the backup plate when the backup plate is turneddown, so that an internal space that a user can sit is defined.