In order to study the changes in the through capacity of the Qianwan one-way waterway in Qingdao Port after the completion of the waterway expansion project and improve the waterway service level，this study establishes a spatio-temporal operation system of the Qingdao Port and a simulation model of the Qianwan Waterway in Qingdao Port based on Flexsim simulation platform.According to the predicted results of the number of ships of different tonnage and types passing through the Qianwan Waterway in different level years，the study carries out the simulation test and analyzes the through capacity and service level of the waterway before and after the expansion project of the Qianwan Waterway in Qingdao Port.The results show that the expansion project of the Qianwan Waterway in Qingdao Port can effectively improve the through capacity and service level of the waterway.The research results can provide important theoretical and decision-making guidance for determining the navigation standards of ships after the waterway expansion.