Simple and visual displacement recording device

The invention discloses a simple and visual displacement recording device. The device comprises upper and lower plates, a toothed plate, a suspension rod, a ratchet gear, a support containing a roller, a flexible rule rotating drum, a flexible rule with scales and an ink box. The ratchet gear comprises a rotating drum, a rotating disk, a pawl, a popup-prevention steel sheet and a gear. When the upper and lower plates generate relative displacements along a specific direction, the pawl abuts against a ratchet of an inner ring of the gear so as to drive the rotating disk to rotate and the flexible rule to move. When directions are opposite, the pawl does not drive the rotating disk and the flexible rule to rotate and move. Through data on the flexible rule with scales, accumulated relative displacements between the upper and lower plates along a motion direction can be rapidly calculated. If the upper and lower plates return to initial positions, the accumulated relative displacements of positive and negative d