Due to lack of a unified standard for performance evaluation of side-lobe blanking, there are few studies on the effect of subarray partition on the side-lobe blanking performance. The performance evaluation parameter of side-lobe blanking—side-lobe blanking ratio is put forward, whose essence is to calculate the proportion of the area satisfying the requirement of the side-lobe blanking in the whole pattern region. The guard channel is constructed by weighted non-phase-coherent accumulation of subarray data directly, which can realize adaptive interference suppression and support the adaptive side-lobe blanking under the interference condition. The simulation results show that the stronger the non-uniformity of subarray partition, the larger the number of the subarray; the smaller the scanning angle, the higher the side-lobe blanking ratio and the better the side-lobe blanking performance of the active phased array antenna.