The search and detection ability of multi functional phased array radar for terminal striking system affects the ATBM operational ability directly. Based on the main factors of affecting search and detection ability, how the detection method affects its detection probability, ability of detection range, how the change of search load affects its search gain performance and how the radar wave direction affects the RCS of TBM which is detected are analyzed in detail. A simulation is given quantificationally to show the effect of each factor finally. The result solves the problem of how to choose a suitable detection mode, how to set the search load and where the radar beam should point.