Abstract: Rolls of steel plates fed to a butt welding and feeding machine, a seamless welding between two adjoining juxtaposed steel plates must be first trimming off both butt ends or leading and trailing edge flanges. After trimming, the trimmed leading and trailing edges flush against each other. Welding torch opposite to a junction line moves along a transversal rail to weld two adjoining juxtaposed steel plates together. Preceding and following steel plates are fed with precision throughout both feeding, discharging rollers driven by servo motors. Steel plate held by a number of jaws urged by springs can reduce inner stress or friction happened between the steel plates; in addition, a gas cutting, machine for trimming off the butt ends, trimmed leading and trailing edges facilitate welding more promptly and efficiently. A good shelf at a front end of the machine can facilitate storing and fixing rolls of steel coil.