A balloon type stent system for treatment of obesity is disclosed. An injection expansion unit and a plurality of distribution expansion units extend in a longitudinal direction of a stent unit body formed by coupling two sheets of synthetic vinyl in the shape of a cylinder. The injection expansion unit has an expansion agent injection port, and the distribution expansion units each have a distribution injection port communicating with a distribution channel. Connection ends are partially cut in the longitudinal direction such that the expansion units are divided into an integrated expansion unit and a separated expansion unit. The injection expansion unit and the distribution expansion units constituting the separated expansion unit are bent outward to form a balloon type stent unit. A tube has a length corresponding to a lumen length of the duodenum, and the tube is connected to the stent unit body by a connection wire.