On the basis of conventional truck mounted workover rig, this product fixes the windproof guy rope on the long-span mast foundation and substructure bottom skid. Compared with the conventional truck mounted workover rig, the operation capacity is exactly the same, but the floor area is small. It is especially suitable for the well pad with insufficient area or unable to fix the windproof guy rope and large operation load requirements. The maximum hook load of free-standing workover rig can reach 1800KN.