Abstract: With the more complex electromagnetic environment, Global Navigation Satellite System (GNSS) receivers were interfered more and more seriously. The interference suppression algorithms based on the uniform array have been widely used in GNSS anti-jamming technology. However, the interference suppression performance of the uniform linear array is strictly limited by the number of array elements. This paper proposed an interference suppression algorithm based on co-prime array. It can obtain a larger array aperture in the case of the same element number of uniform array, improve the performance of direction of arrival (DOA) estimation while it does not need to know the number of the interference. The proposed method uses the sparse spatial spectrum estimation method to estimate the DOA of interference. Then the interference subspace is formed based on the estimated DOAs of interference, and orthogonal subspace projection algorithm is used to suppress interference. The simulation results verify the effectiveness of the proposed algorithm.