Abstract: Based on supervision work practice this paper points out the Three step working method . By clarifying work standards,process Inspection,comparison of inspection results with work standards ,We can determine whether the work is qualified.This method is applicable to process acceptance,inspection batch acceptance,material acceptance,engineering cost,engineering progress and engineering safety etc.The Three step working method aims to foster active consciousness of the engineer.The Three step working method is the effectual way to improve ability of the engineer.