The utility model discloses a damage-free oil tube centralizer for petroleum industry, which has the effect of centralizing pumping well production strings without damage to sleeves, and is a tool for reducing accidents of break of sleeves and break and leakage of an oil tube during the process of producing well production. The centralizer comprises an oil tube pup joint; a damage-free centralizing block is arranged on the circumcircle of the oil tube pup joint, so as to form the centralizer; and a spiral guiding groove at any angle from 42 to 48 degrees is arranged on the outer surface of the centralizing block, so as to ensure that liquid flow is smooth. The spiral guiding groove of the centralizing block adopts arc groove design, so that the contact area is increased, and liquid flow is smoother. The effect of sleeve protection is achieved through the centralizing block made of wear superstrong nylon material while the oil tube is centralized, and the protection effect on inclined section oil tube is also achieved. In addition to the performances of the original centralizing block, the damage-free oil tube centralizer also solves the problem of damage to sleeve, has reasonable performance, and is suitable for application.