The key optimal goal of manual order picking system is shortest picker route, thereby best times. Picker route stochastic model under sorted storage S-type picking for logistics distribution center manual order picking is built. It makes model approximation calculation and simulation result under three order arrival frequencies and space ratio. It is stated that well approximation between model and simulation results under the condition of permission difference are obtained. The model lays the foundation for building stochastic service system model of distribution center manual order picking.