The characteristics of two dimensional bar code are analyzed, then the technological characteristics and the composition of logistic bar code are discussed.Through the analysis of application in medicine trade logistics management system,the PDF417 two dimensional bar code is used to make out a selling invoice, medicines stock,etc. With PDF417 two dimensional bar code , the medicine trade logistics management system overcomes many difficult problems, makes the whole system to be more efficient, completes the plan, organization, coordination and control of trade partners, logistic, information ,business,finance etc., and strengthens the connection between the trade partners.