Classic Deep Convolutional Neural Network (DCNN) models have demonstrated notable efficacy in segmenting remote sensing images. However, their ability to enhance the precision of water body detection, particularly for smaller ones amid intricate backgrounds, remains challenging. This paper proposes the Negative Laplacian Filter (NLF) method as a solution, enhancing regional color contrast during preprocessing to capture more intricate details effectively. Furthermore, a novel approach employs a differential dualencoding structure that encodes diverse spectra based on their spectral attributes. Lastly, leveraging prior insights from remote sensing, we introduce the Weak Label Weight Adjustment (WLWA) operation for refining predicted images in post-processing stages. The proposed model significantly outperforms the comparison models on our remote sensing water body dataset.