In order to obtain the optimum structure parameters of sine exponential curve type trenching blade, according to the equation of sine exponential curve, totally 15 types of furrowing blade were designed and test in soil bin was conducted. A central composite design method of the second order regression orthogonal was carried out with bending angle, bending radius and sliding cutting angle as experiment factors and with power consumption and stability of groove depth as response values. By using Design-Expert 8.0.6 regression analysis method and regression surface method, both single factor and interactive factor on response values were analyzed. Combined with nonlinear optimization calculation method, the structural parameters were calculated optimally. The results obtained under the conditions of soil strength was 0.29MPa, moisture content was 16.2%, in terms of significant degree, the influence factors of power consumption were bending angle, sliding cutting angle and bending radius; the influence factors of stability of groove depth were sliding cutting angle, bending angle and bending radius. The optimum parameter condition of the sine exponential curve type trenching blade after optimizing was 86.75°of bending angle，12mm of bending radius and 13.8°of sliding cutting angle. At this time, power consumption achieved theoretical optimum value of 32.32kW, stability of groove depth was 95.6%. Through verification by an experiment under optimum condition, the experiment value of power consumption was 34.27kW, stability of groove depth was 92.82%, which indicated that the experiment results and predicted results were consistent, and regression models established by the experiment were appropriate. According to comparison of trench experiment before and after parameter optimization under two different soil conditions, power consumption fell by 4.28kW and 4.23kW, respectively; groove depth stability were increased by 7.12 and 7.02 percentage points, respectively. According to comparison of existed trenching blade under two different soil conditions, power consumption fell by 7.68kW and 6.91kW, respectively; groove depth stability were increased by 14.34 and 8.34 percentage points, respectively. Research result of the article provides a theoretical basis for the sine curve type furrowing blade optimization design.