Portable core drill rigs are lightweight, detachable coring devices for shallow geological sampling in inaccessible areas, classified by power, split structure and drilling depth. By power supply, gasoline-powered portable rigs work independently in remote mountains without power grids, the most popular field type. Electric small core rigs run quietly for suburban geotechnical surveys with accessible mains. Pneumatic portable models feature explosion-proof performance for underground tunnel sampling. According to split design, a fully split portable core drill rig can break into multiple small modules each under 80kg for manpower transport on steep slopes. Semi-portable skid units can be towed by small vehicles for flat hilltop construction. Classified by drilling depth, mini portable rigs drill within 50m for soil and shallow rock sampling. Medium portable core drill rigs reach 50–150m for small mineral reconnaissance and road slope investigation. Most match small diamond bits and simple wireline tools to recover intact core samples. Compact size, easy assembly and low transport cost make them ideal for forest, mountain and narrow-site exploration projects.