A practical engineering of the long-short-pile composite foundation is presented. By means of finite element analytical method, the stress distribution and displacement of four foundations reinforced by long-short-pile composite foundation, whole long piles, whole short piles and raft foundation under the same geological conditions have been compared and analyzed. The results show that under the same loading condition, the characteristics of foundation reinforced by whole short piles are approximate to those of natural foundation while the characteristics of foundation reinforced by long-short-pile composite foundation are similar with those of foundation reinforced by whole long piles.