Abstract: The transient interference can dramatically degrade the performance of over-the-horizon radar. The traditional interference suppression methods need to suppress the sea clutter, and only can suppress the strong transient interference, not mitigate the weak one and the noise. A novel interference suppression method is proposed based on the low-rank matrix completion. Firstly, the proposed method detects the interference via the Teager-Kaiser operator, subsequently excises the interference data. Then, considering that the Hankel matrix of clutter-plus-target signals is low-rank, the matrix completion method is exploited to recover the interference- removed signal. The proposed algorithm can suppress not only the strong interference, but also the weak one and the noise, improving the signal to noise ratio of echo. The simulation and experimental results demonstrate the effectiveness of the proposed method.