Abstract: To develop CAD of plow body surface, 12-paramter plow design method is presented on the basis of plow velocity as primary design parameter. Through analysing design principle of plow body surface, mathematical model of plow body surface is established and a system of software and hardware of CAD is developed. Plow body surface drawing and its expending drawing with all sorts of plow body width is calculated and drawn by this software. The speed of drawing and expending plow body surface is 20 times faster than normal design,and the precision is high.Depending on the CAD system, NO. 34 plow body has been trial produced and tested. This article describes the comparative test results between No. 34 and BT-30 plow body in detail.Through all sorts of trial manufacture and tests, it has proved that performance of No. 34 plow body is better than BT-30, with resistance reduced by 10 percent.