Reckoning on the strong interfere of background information to anomaly detection for hyperspectral image,a kind of anomaly detection algorithm based on background error cumulation is proposed.First,it constructs the background subspace.Then it projects every pixel into this subspace to obtain background error data for later anomaly detection,which suppresses background and makes target stand out.Experiments on real hyperspectral image show that the proposed algorithm outperforms other algorithms,and obtains better detection results.