Abstract: After analyzing BM algorithm and some important improved algorithms, a new improved algorithm called Y_BMHS is put forward in this paper. With a two-dimensional array, the algorithm considers the uniqueness of text string’s last two interval characters and pattern string’s first character. The proposed algorithm makes the maximum displacement enhance to m+3, and the occurrence probability and match speed are also improved. The experimental results show that the Y_BMHS algorithm performs better than BM, BMH, BMHS and other improved algorithms as well.