Abstract: This article clarifies the comparison between EPLAN and other software on electrical three-dimensional wire harness designing, and then it mainly introduces how to use EPLAN（P8,Harness ProD,Library） to do electrical three-dimensional wire harness design of tractor, it also introduces the design profile, using the electirc design software EPLAN can improve the design efficiency, which can also makes the product wiring harness installation more reliable and beautiful.