Abstract: As a drug ban models, outside planting substitutionnot only is the eradication of foreign drug sources on the fundamental strategy of harm, but also an important strategy to improve the level of food supply,and ensure food security of Yunnan Province. From the perspective of food security, in concluding the effectiveness of outside planting substitution andanalyzing the main factors of outside planting substitution of Yunnan, this paper has proposed that outside planting substitution is an opportunity to coverpart of the food gap and balance the food's supply and demand and then, this paper has also proposed a new idea for food security in Yunnan Province.