Abstract: A fixing device for attaching to a lumen wall, the device including a base (18) and a fixing mechanism (5) fixed on the base (18). The fixing mechanism (5) includes a housing (5a), at least a set of clamping brackets (3), and a rotating shaft (7). A bracket hole (3b) is formed on each clamp bracket (3), and the rotating shaft (7) passes through the bracket hole (3b) and fixes each set of the clamping brackets (3) on the housing (5a) of the fixing device.