High frequency welded steel pipe mill is the main equipment in the steel pipe production line, mainly used to produce steel pipe with material of mild steel and low alloy steel. It uses roll forming theory to coil long steel strip of a certain specification into pipe barrel without any intermittence and form longitudinal seam joint under the force of squeeze roller. And it uses induction welding to heat the longitudinal seam. That is, feed steel strip of a certain specification into the mill and coil it into pipe blank through forming roller. Then under skin effect and proximity effect of high frequency electric current, the current will be concentrated on the bond surface of the pipe fringe, welding it into tube blank quickly. After cooling, sizing and broad straightening, the needed pipe will be produced.