A three-axis end-limiting tool placement structure includes a basic face, a first-end three-axis limiting portion, a second-end X-axis limiting portion, and a sliding Z-axis limiting piece at the second end. The first end of the three-axis limiting part includes one end abutting wall, two lateral limiting walls and a pressing edge, so that the first end of the tool placement bar reaches the X, Y, Z axial limiting state. The X-axis limiting portion is used to limit at least the X-axis of the second end of the tool placement bar. The sliding Z-axis limiting piece at the second end includes a track set and a sliding cover, and the sliding cover has a release and locking positions. When the sliding cover is in locked position, the cover is blocked on the top surface of the second end of the tool placement bar, thereby forming the Z-axis in limiting state.