Multidimension 01 knapsack problem is a typical NonDeterministic Polynomial problem. In view that ant colony algorithm solving often have local optimum and slow convergence speed problems, this article propose an improved ant colony algorithm. Based on the introduction of leap frog algorithm clustering thought, the ants have been developed into two groups with different culture, which improves the global search ability. The greedy strategy modified formula is applied in order to improve the accuracy of calculation. The formula is further simplified by roulette algorithm. Simulation results indicated that the modified algorithm improves the accuracy and global search ability.