The invention relates to an auxiliary operation device of a ground line mounting device. The auxiliary operation device comprises a frame type supporting frame. The bottom of the supporting frame is provided with a base. The bottom of the base is provided with a plurality of rollers. The middle part of the base is provided with a multi-grade telescopic hydraulic cylinder which is mounted vertically, an electric hydraulic pump which is connected with the hydraulic cylinder through a hydraulic pipe, and a storage battery which is used for supplying electric energy to the electric hydraulic pump. The top end of the piston rod of the hydraulic rod is hinged with an openable/closable annular hoop sleeve. A plurality of supporting bearings are rotatably mounted at the inner circumference of the annular hoop sleeve. The annular hoop sleeve comprises two arc-shaped troughs. One side of the two arc-shaped troughs is hinged through a hinge, and the other side is correspondingly provided with at least one set of ear plates. Two ear plates in each set are respectively provided with at least one positioning hole correspondingly. A locking bolt penetrates through the two positioning holes when the two arc-shaped troughs are buckled. The auxiliary operation device of the ground line mounting device has advantages of simple structure, high convenience in realization, time-saving and labor-saving effect in operation, high accuracy and high reliability in mounting, and thorough settlement for a mounting device operation problem.