Perineal region drainage type underpants comprise drainage tubes, air bags, an underpants body, a drainage cavity bag, butt joint pieces, connecting pieces, connecting lines, one-way valves, a springII, a sealing plate and a sealing ring. The pain of a patient after an operation can be relieved when the perineal region drainage tubes move, the patient can actively get out of bed and does exercises properly after the operation, blood circulation is promoted, and the healing of tissue of the operation area is promoted. The drainage cavity bag is provided with a drainage cavity bag inner cavity,a connecting belt, a flow guide pipe and a matching groove I; the butt joint pieces comprise fixing heads and butt joint pipes; one end of each drainage tube is fixed in the human body through the corresponding air bag, and the other end of each drainage tube is located outside the hips of the human body; the drainage cavity bag is connected to the back fly of the underpants through the connecting lines; the butt joint pieces are fixedly connected into the matching groove I through the fixing heads; the connecting pieces are connected between the drainage tubes and the butt joint pieces; theone-way valves are arranged at the bottom ends of the fixing heads and located in the drainage cavity bag inner cavity.