The utility model discloses an anti -roll smooth fixture of cylinder section bar, its two connecting blocks that set up including the symmetry, two the connecting block concatenation is fixed and is constituted a whole together, and the lower extreme is formed with half the cylindrical recess respectively on the whole, two the axis of recess each other becomes 90 crisscross settings. The utility model discloses a fixture can realize totally that four ascending anti -roll cunnings in side are spacing, rely on special bolted connection mechanism can adjust fixture to the obvolvent area of the section bar body with seize the pretightning force on both sides by the arms, can also realize that the commonality is strong to section bar body diameter range's regulation, some cylinder section bar stock grounds outer to the trade also possess the suitability.