The problem of detecting targets in the cluttered circumstance with wide-band high-resolution radar is studied. A way of improving SCR(Signal-to-Clutter-Ratio) is presented by linear integration filtering in polarization domain. With the intrinsic high-resolution characteristic of wide-band waveform, one-dimension range profile of radar target can be obtained. The number and distribution of intense scatterers in radar returns can be estimated. A polarization target detection method is presented based on the correlation of these intense scatterers in various resolution cells. SCR can be improved efficiently and so can the detection performance of radar. The experiment results show that this method is a very effective detection strategy for extended targets.