The invention discloses a measurement device for measuring the abdominal shell expansion amount of an axial flow type centrifugal compressor and relates to the technical field of the design of a turbine mechanical structure. The device is used for measuring the expansion amount of an abdominal shell during the operation process of the axial flow type centrifugal compressor. A fixed base is fixedly connected with a base of the axial flow type centrifugal compressor. A probe fixing cylinder is arranged in a piston barrel. A distance measuring instrument is arranged on a distance measuring instrument mounting frame. One end of the probe fixing cylinder is connected with an elastic part and extends into the piston barrel. A probe is arranged at the other end of the probe fixing cylinder. A dial plate is fixedly arranged on the probe fixing cylinder in the circumferential direction of the probe fixing cylinder. The distance measuring instrument obtains the expansion amount of the abdominal shell through measuring the displacement of the dial plate. The measurement device is widely applied to the measurement of the expansion amount of the abdominal shell of the axial flow type centrifugal compressor. The measurement device is stable in structure, high in measurement precision and high in reliability. The measurement device ensures the stable operation of an axial flow type centrifugal compressor unit.