Abstract: Method of target identification using millimeter wave detection technique is studied.Based on the analysis of millimeter wave characteristics of tank,metal plates and water,the combined distinguishing method is put forward,judging the energy,pulse width of the signal,the time interval between the two pulses and the velvet degree of target's surface.Principles of tank target identification were set up.The distributing histograms of different characteristics are built using the statistical method.Then the curves of probability density are given.According to detection probability,thresholds of characteristics are determined.The identification precision is improved by the enactment of more thresholds.The result of theoretical analysis proves the validity of the identification method for close target and provides a reference approach for other relative detection system.