Abstract: ArcSAR has the advantages of high resolution, large field of view, and short revisit period. Therefore, it receives more and more attention in the scientific literature in recent years and is gradually applied to ground monitoring. The complex motion trail(arc) of the ArcSAR increases the difficulty of the imaging algorithm. Although the time domain algorithm can obtain high-precision imaging results of the system, this type of algorithm is computationally inefficient. Therefore, this paper proposes a novel fast imaging algorithm for ArcSAR. Firstiy, the geometric model and signal model of ArcSAR are given. Then the principle of the algorithm is discussed and the two-dimensional frequency domain matched filter is deduced. Besides, the applicable condition of the algorithm is also discussed. Finally, the application condition of the proposed algorithm are verified by simulation experiments, and the imaging efficiency and imaging quality of the time domain imaging algorithm and the fast imaging algorithm proposed in this paper are compared.