The invention discloses a pre-articulated handsaw with a counterbore-and-penetration-rod fastening structure, comprising saw blades and a saw frame body, the front end of the saw frame body is articulated with a movable adjusting piece, both ends of the movable adjusting piece are provided with a saw blade assembling end and a tensioning end, the saw blade assembling end of the movable adjusting piece is buckled with the saw blades, the other end of the saw blade is buckled with the lower part of the back end of the saw frame body, the tensioning end of the movable adjusting piece is providedwith an adjusting screw, a counterbore body is arranged at the upper part of the back end of the saw frame body, the adjusting screw is matched and connected with the back end of the saw frame body by the counterbore body, one end of the adjusting screw is provided with a nut which can control the tightness between the saw frame body and the movable adjusting piece; the movable adjusting piece isarticulated at the front end of the saw frame body, thus the structure is new, the saw blades are assembled and disassembled conveniently; a back side postpositioned pull bar tensioning structure is adopted to adjust the pulling force, thus fully guaranteeing the tension of the saw blade; a counterbore hidden pull bar assembling structure can simplify the overall structure.