The main lobe interference suppression technique for wideband noise interference is studied in this paper, which is based on the space-time adaptive processing (STAP). One is the singular value decomposition (SVD-STAP) algorithm, it can have better beam-conserving ability when the expected signal power is low or even zero power, but it is needed in every narrow band of the division, and the result error of the weighted average will increase because of the large computation, moreover, when the interference to noise radio (INR) is more than 70dB, the growth rate of the signal-to-interference noise ratio (SINR) improvement slows down. Based on this situation, we propose a focusing matrix algorithm (FSVD-STAP). The method doesn’t need to know the direction information of the interference in advance, and the calculation error will be relatively reduced. The simulation results show that the two methods can suppress the wideband noise interference which falls on the main lobe, and they have good beam-pattern and SINR improvement.