During the construction of electric power construction, there are more and more stainless steel and low alloy steel dissimilar steel welding, and this kind of dissimilar steel welding, welding cracks tend to be more serious. Often encountered in construction process to produce the phenomenon of crack, this paper aimed at the defects made the repair process, using this technology to repair, repair a qualified rate of 99% or more, greatly reduces the cost, improve the efficacy. Key words: welding crack; Repair; Percent of pass