Due to the limitation of dynamic range, a single still image is usually insufficient to describe a high contrast scene. Fusing multi-exposure images of the same scene can produce a resulting image with details both in bright and dark regions. However, they may be sensitive to the exposure parameters of the input images. To improve the robustness of the method, a novel layered-based exposure fusion algorithm is proposed in this paper. In our algorithm, a global-layer is introduced to improve the robustness of the fusion method. The global-layer is employed to preserve the overall luminance of a real scene and avoid possible luminance reversion. Then details are recovered in gradient domain by a Poisson solver. Experimental results show the superior performance of our approach in terms of robustness and color consistency.