In order to optimize the delivery path of express delivery, a mathematical model based on time window is given. In this study, improved AHP-GA algorithm is used to optimize multi-target vehicle routing, and median Analytic Hierarchy Process (AHP) is used to compare the weight coefficients of multiple sub-targets, and it is not susceptible to extremes. Thus, the multi-objective optimization problem is transformed into a single objective optimization problem. The simple natural numbers are used to code the vehicle path to avoid duplication of the paths. The customer's requirement for arrival time window, including the opportunity cost of the vehicle to arrive before the agreed time, and the cost of the fine after the agreed time. Finally, this study takes 1 distribution center and 20 service customers for example, the mathematical model constructed in this study is optimized by using traditional GA algorithm and using improved AHP-GA algorithm respectively. The simulation results show that the optimal solution can be obtained efficiently by using improved AHP-GA algorithm in multi-objective distribution path optimization problem.