Hydraulic pipe cutter for geological exploration

The utility model particularly relates to a hydraulic pipe cutter for geological exploration, which is driven to rotate by rotation of a drill rod and comprises a piston shaft (3), a positioning rotating shaft (4), a pipe cutter outer body (2), a conversion joint (1) and a pipe cutter tool bit (5), and the piston shaft (3), the positioning rotating shaft (4), the pipe cutter outer body (2) and the conversion joint (1) share the same axial center line. One end of the adapter (1) is in threaded connection with a drill rod, and the other end of the adapter (1) is in threaded connection with the pipe cutter outer body (2); a center hole with an opening in the top is formed in the pipe cutter outer body (2) and allows the piston shaft (3) to penetrate through, an outer circular hole with an opening in the side is formed below the outer center hole and allows the pipe cutter tool bit (5) to be opened and closed, and the center hole is communicated with the outer circular hole; and the pipe cutter tool bit (5) is hi