This kind of drilling rig has two types: the integral skid-on-trailer drilling rig and the individual skid-on-trailer drilling rig. The integral skid-on-trailer drilling rig means that all components, such as the mast, substructure, crow block, drawworks, travelling block (top drive), etc. will be installed on a trailer for quick short-distance transportation, which doesn’t need rigging down. The individual skid-on-trailer drilling rig means the mast and substructure will be trailer-moved separately. It is applicable for the harsh road condition and long-distance transportation.