To overcome the affection of heavy clutter and dim target intensity on small target detection, an efficient morphological method through clutter elimination is proposed. The proposed adaptive method imports the property of the target region into the morphological operations, which apparently improves the performance of the method and can largely enhance the dim small target. So, the target can be easily detected through a target detection algorithm, which is proposed based on the adaptive morphological method for clutter elimination. Experiments show that the proposed method can accurately eliminate the clutter background, and thus largely enhance and efficiently detect the small target.