To utilize the advantages of polarimetric imaging in target detection and recognition,the mechanism of depolarization in polarimetric detection and the influences of surface scattering and volume scattering on polarization degree are anayzed.Illuminated with 808 nm diode laser,the back scattered light of target is accepted by Cassegrain telescope.Two images are imaged on CCDs through Polarization beam splitter.Two orthogonal polarization state images can be obtained through once measurement,and then intensity and polarization degree can be calculated.Images coded with intensity and polarization degree are acquired.Experimental results show that intensity image can not distinguish targets when having similar albedo,whereas the polarization degree image can distinguish targets.Using HSI pseudocolor coding method to fuse the intensity and polarization images,the aim of target detection and recognition are achieved.