Abstract: To properly control the forming seam pout amount of the JCOE LSAW pipe，and improve the weld performance and quality, based on the production practice and experiences over many years，a complete set of process methods for optimizing the edge pre-bending radius to control the pout amount is summarized, involving the design and measurement of the pre-bending radius of steel pipes with different sizes. Owing to verification via the production practice concerning more than 300 steel pipe sizes，relevant purposes are met，including ideal steel pipe shape size and pout control effect，particularly，the control effect is so obvious for hi-grade steel JCOE LSAW pipe production. Described here in the article are the design principle，the method and the empirical formula summary of the pre-bending radian，and also expounded is the application effectiveness in the daily production. The above mentioned process achievement is worthy spreading up and using in similar production lines.