Abstract: This paper introduces a kind of microstrip slot array interrogation antenna under single-pulse work system. Itdesigns a 6-unit microstrip slot array antenna. Through choosing appropriate antenna element and adjusting the amplitude andphase characteristics of feed network, antenna array can work in bandwidth of 13% with the standing wave less than 1.6,difference patterns being symmetric, null depth of difference beam lower than -30dB, and without any puncture phenomenonwith the difference beam. It shows good engineering application value.