The utility model belongs to the technical field of vegetation and analysis sampling, concretely relates to sampling device of assay trees annual ring, including the drill bit, the drill bit is the open tubular structure of one end, and the front end of drill bit is equipped with zigzag incision on the opening end terminal surface, it is equipped with the ring channel to be close to zigzag incision position department on the inner wall of drill bit, be equipped with cutting tool in the ring channel, cutting tool's one end is articulated with the ring channel, and messenger cutting tool can be to in drill bit center swing or closing at the ring channel, in the time of in cutting tool closes at the ring channel, cutting tool's knife tip protrusion drill bit inner wall forms the barb column structure, and the drill bit is when corotation, and cutting tool can keep in the ring channel, and during the drill bit reversal, the reel in the drill bit can be with cutting tool jack -up. The utility model discloses a drive unit driver bit corotation and reversals such as motor, during corotation, zigzag incision down -cutting, cutting tool pops out during the reversal, cuts off the reel, can accomplish the sample of trees reel high -efficiently and develop the research of the aspects such as annual ring and global climate change response of being correlated with.