With the emergence of Big Data applications in recent years, nowadays data centers are usually deployed with various kinds of Big Data applications and managed by resource manager such as Mesos. Mesos mainly focuses on computing resource and storage resource (CPU and memory), while ignoring network management. But research shows that efficient network resource management is crucial to optimize performance. In this work we present a network management mechanism based on SDN(Software Defined Network). This mechanism can allocate weighted network resource to different jobs based on preconfigured policy. It can allocate more bandwidth to high-priority job to optimize performance while keep the network performance isolation at the same time. We have implemented a prototype system based on SDN controller, floodlight and the experiments show that this prototype has strong usability and high expansibility.