With the popularity of cloud computing, cloud computing enterprises are launching cloud storage services, which are becoming more and more attention and use as an emerging network storage technology. In the application process of cloud storage, object storage service interface is growing rapidly, so as to ensure stability and reliability, the flow control of object storage service is required. Based on the token bucket algorithm, this paper put forward three kinds of flow access control strategy to cloud storage service interface, which can provide fine-grained flow access control for different user priorities and service interfaces.