Modern radar requires good performance of low intercept. In the presence of ever-increasing number of low Radar Cross-Section(RCS) targets，modern radar must decrease the detection threshold for signal processing in order to improve its detection capability of these kinds of targets. Then it can undertake data processing by incoherent integration of echo amplitude along the contrail of target movements to obtain lower false alarm rate. Because of the limitation of volume, weight and power consumption in air radar, the application of finer data processing method is much important for the increase of detection range，which brings forward better processing ability for the radar system. This work makes use of Track-Before-Detect(TBD) for improving detect range，and gives parallel processing architecture for performance computation. The results of processing on the real data of a certain air radar using the prposed method indicate that TBD can improve system detection performance greatly.