Drilling tool for clay layer drilling and coring

The utility model discloses a drilling tool for clay layer drilling and coring, and relates to a drilling tool for soil layers or rocks, in particular to a drilling tool which is used for clay layer drilling and coring and is characterized by a conduit of drilling fluid. The utility model aims at providing a drilling tool for clay layer drilling and coring, which can improve the core recovery rate and avoid orifice spouting. The drilling tool comprises a core barrel (1), a sliding sleeve (2), a sliding shaft (3), a drilling rod connector (4), a connector hollow channel (41), a sliding shaft upstream limiting block (31), a sliding shaft hollow channel (32), at least one upper through hole (33) and at least one lower through hole (34); the sliding shaft can drive the sliding sleeve to rotate around the axis of the core barrel; when the upper end surface of the sliding shaft upstream limiting block is in contact with the sliding sleeve, each through hole is positioned above the upper end surface of the sliding s