An encouragement strategy which can achieve global optimal and stable solution simultaneously is presented.In the experiment

the postman problem is selected as the example

and the three strategies which include Shapley value strategy、average share strategy and encouragement strategy are used to compare with.The experimental data show that the Shapley value strategy and average share strategy are very inefficient

and can not ensure the stability of the coalition.However the encouragement strategy is very efficient and can achieve global optimal and stable solution simultaneously.In the end

the superiority of the strategy is analyzed.