It is immediately significant of study on optimal method of cargo flows distribution in large logistics park. It becomes more complicated when the transportation of resources and destinations are all random variables and the transportation is limited by path capacities. This paper sets up a mathematics model through analysis to the transportation mode in large logistics park based on the random service process to solve the cargo asymmetric problems in large logistics park. Last we design the random decisive genetic algorithm to solve model and get satisfied result. Through analysis of problem, we can easily find the suitable transportation from the resource to destination and solve the bottlenecks in logistics park. Last the analysis result of an example indicates that the method is practical and handle.