The invention discloses a screw outer thread cleaning tool, and relates to the field of tool articles. The screw outer thread cleaning tool is composed of a semicircular head 1, a blade 2, an elasticrubber band 3, a connecting rotation shaft 4, an elastic rubber band hook 5 on the blade, an elastic rubber band hook 6 on a right semicircular head body, a screw 7 needing to be subjected to thread cleaning, a left semicircular head body 8, the right semicircular head body 9 and a handle 10, the handle 10 and the semicircular head 1 are fixedly connected together, and the semicircular head 1 is divided into the left semicircular head body 8 and the right semicircular head body 9. The left semicircular head body 8 and the blade 2 are movably connected together through the connecting rotation shaft 4, and the blade 2 can rotate around the connecting rotation shaft 4. The two ends of the elastic rubber band 3 are hung on the elastic rubber band hook 5 on the blade and the elastic rubber bandhook 6 on the right semicircular head body. Due to the elasticity action, the blade 2 is downwards pulled, and the screw 7 needing to be subjected to thread cleaning is located in the semicircular head 1. Through the design, the beneficial effect that the screw thread can be cleaned is achieved.