The invention discloses a special sampler used in detection of a cable of an electric power system. The sampler comprises a base extending leftward and rightward; a transverse rail extending leftward and rightward is fixedly arranged on the central part of the base; the left part of the base is provided with a rotation head rotating under the driving of a power unit; a clamp used for clamping the cable is arranged on the rotation head; the cross rail is provided with a transverse base which can only slide along the transverse rail; the right part of the base is equipped with a transverse control device used for controlling leftward and rightward movement of the transverse base; the transverse base is fixedly provided with a longitudinal rail extending forward and backward; a longitudinal base which can only slide back and forth along the longitudinal rail is mounted on the longitudinal rail; a blade matching with the clamp is fixedly installed on the longitudinal base through a blade clamp; and the transverse base is equipped with a longitudinal control unit which controls forward and backward sliding of the longitudinal base. The special sampler is firm in fixation and fast in cutting; a cut section is neat and does not deform; a cutting size is accurate and has small errors; the sampler is beneficial for improving detection precision and convenient to operate, and can be operated by only one person; and the sampler is high in operation security.