Array roll shaping ERW welded pipe curvature radius on-line measurement arrangement

The utility model provides a curvature radius online measuring apparatus for an array roll forming ERW welded pipe, comprising a measuring support, a detection dial gauge, a detection end output port and a measuring value output port, wherein, the measuring support has a cylindrical structure; a through hole is arranged in the internal center of the measuring support along the axial direction, and a groove is arranged on one end of the through hole to form two equal altitude pivot points on the end part; the detection dial gauge is provided with a loop bar and a display panel which is fixed on the loop bar; a detection probe is connected with data of the display panel through a spring structure which is arranged inside the loop bar and reciprocates in the loop bar which is arranged and fixed in the through hole of the measuring support form a relative end of the groove in a fitting way; the detection probe externally protrudes out of the pivot points. The utility model can highly and precisely measure the cur