This paper presents a new small target detection approach, which is based on multi-resolution distance map and background texture analysis. Through multi-scale wavelet decomposition of background textures and local energy calculation, feature vectors of each point are obtained. According to these feature vectors, a distance map corresponding to these features can be derived, and target detection is performed on this distance map. The histogram of distance map is employed for the automatic selection of threshold value. Experiments show that this approach can achieve quit satisfactory results.