Abstract: A binding device for indicating the amount of negative pressure suction to use in a binding operation to treat hemorrhoids. The device is simple and convenient to use, and allows for more accurate binding operations. The binding device has a shell, a pushing pipe at the shell's front end, and a suction tube in the pushing pipe. A negative pressure device is in the shell. A scale cylinder has a cylinder body divided into two cavities and a piston piece within. The negative pressure device has a suction port in communication with the rear end of the suction tube and connected with one of the cylinder cavities. The cylinder body can move relative to the shell, and the shell has a scale part corresponding to that movement. The binding part is sleeved at the front end of the suction tube.