The invention discloses a blade part magnetorheological fluid flexible clamping device and method, belongs to the technical field of part clamping, and relates to the blade part magnetorheological fluid flexible clamping device and method. The clamping device consists of a tenon magnetorheological fluid clamping mechanism, a blade body magnetorheological fluid clamping mechanism and a magnetorheological fluid filling device; the blade body magnetorheological clamping mechanism is connected with the upper portion of the tenon magnetorheological clamping mechanism through bolts; and a female diefilling port and a male die filling port in the blade body magnetorheological clamping mechanism are respectively connected with a channel in the magnetorheological fluid filling device. In the clamping method, a blade is firstly placed in a base tenon positioning groove, a blade tenon part is clamped by a blade tenon magnetorheological clamping mechanism, and the lower section of the blade is machined. After the lower section of the blade is processed, the lower section of blade body is clamped by the blade body magnetorheological clamping mechanism, and the upper section of the blade is processed. According to the method, under the condition of one-time clamping and positioning, the whole surface of the blade is machined, the integral machining precision is guaranteed, and the method issimple, convenient, rapid and accurate to implement.