Abstract: This article clarifies the disadvantages of CAD on spreader ’s electrical designing for tractor, and then it describes the advantages of electrical designing software EPLAN,and then it describes the comparison between CAD and EPLAN;It mainly introduces how to use EPLAN to do electric system papers design of tractor, it also introduces the design profile, using the electirc design software EPLAN can improve the standardization consistencies and motorization of electric design, which can also makes the work more effective and more accurate.