To the question of particle images segmentation with uneven illumination background,a novel method is proposed based on homomorphic filtering,Top-Hat transformation and watershed algorithm in this paper after discussing the characteristic of various common segmentation algorithms.Firstly,homomorphic filtering is carried out on particle image frequency region space,which weakened low frequency component and strengthened the high frequency component appropriately,to make the whole image evenly.Then,Top-Hat transformation is adopted to remove a large area of the target background and segment the targets active area.Finally,watershed algorithm is used for segmentation of adhesive particles.Experimental results show that the proposed method is simple and practical,and can segment the targets form uneven illumination particle images.