An anti-interference system based on the adaptive algorithm is proposed for the Global Navigation Satellite Systems (GNSS) anti-interference application. The proposed system utilizes the low complexity adaptive algorithm for interference suppression and beamforming. The constraint condition for the beamforming algorithm is per satellite constraint, which ensures each GNSS satellite has the largest signal to interference and noise ratio (SINR). The adaptive beamforming with restraint is translated into the adaptive filter problem without restraint by generalized sidelobe canceller (GSC) structure, which could be realized easily by adaptive algorithm. It is confirmed by the practical test that the proposed system can suppress interference and form the multi-beam very effectively with low complexity.