As a hot spot of the algorithms of swarm intelligence, Ant Colony Optimization is proposed by an Italian scholar M.Dorigo by simulating the foraging actions of ants. This paper introduces the principle of this algorithm and its merit and demerit in great detail. It proposes an effective method named “four steps” based on others scholars’ “three steps” to choose the optimal combinational parameter of ant colony algorithms, then analyzes the improved algorithm of ant colony. At the same time, several kinds of algorithms are compared and analyzed in performance in solving TSP problems through the experiments. the optimal results can be obtained.