In view of the present weak points of the conventional average energy kerma factor method,the average displacement kerma factor method calculating the displacement damage in the different energy grouping structure is presented based on Si displacement kerma factor function table.Displacement damage of several radiation sources are calculated with this method.The results show that the discrepancy of dis-placement damage using the average energy method is about 17%,and it is about 4% using the average dis-placement kerma factor method.The results also show that the displacement damage for the different neutron distributions in same energy group do not significantly change with the average displacement kerma factor method.