Abstract: Energy forest as a renewable resource had gained more and more attention，and related harvester research had become a hot spot.The nondestructive header of energy forest cutting units was designed，with overall welded frame，double ring and sloping 8 degree angle between circular saw and horizontal plane，minimum location limit.This unit attached 4MG275type cotton straw harvesters by ZHONGNONGJI′s manufacturing can perform testing experiments.The test results showed that，under condition of saw cutting line speed in a certain set，leakage rate of cutting，broken stubble rate and stubble height were positive correlations with machine walking speed.Broken stubble rate than other models reduced by 1%-1.5%.