The invention relates to a dynamometer, and belongs to the field of aircraft testing tools. The dynamometer is applied to carrying out rigidity tests on rod pieces such as an aircraft pilot operating rod, a cyclic rod, a pedal plate and the like, and can measure a pushing force and a pulling force born by the rod pieces. The dynamometer comprises a shell, a deformation rod, a holding sleeve, a shaft, a compression nut, a screw and a dial indicator, wherein the deformation rod is embedded inside the shell and locked by using the compression nut, the holding sleeve is fixed at the external part of the shell through the shaft, and the dial indicator penetrates through the shell and is pressed against the top end of the deformation rod and tightened by using the screw, thereby being combined into the dynamometer. When the dynamometer is used, the shell is placed inside an operating rod, a pushing force or a pulling force is manually applied to the holding sleeve, deformation occurs in the deformation rod so as to generate displacement, and the dial indicator is converted into reading and reflected to a dial plate according to variations in displacement. The dynamometer provided by the invention not only can ensure operations in a narrow space, but also can meet precision requirements of force measurement. The dynamometer is small and flexible, simple to operate, low in manufacturing cost, and very applicable to rigidity tests of the rod pieces.