The Neutral Beam Injector (NBI) is one of the main plasma heating methods for Experimental Advanced Superconducting Tokomaks (EAST). In order to provide unify time-order control, control the power supply and ensure the NBI system stable and reliable effectively, the control system is designed. As the center of the control system, control server plays a crucial role which can control the input/output services of the whole NBI system, verify whether the experimental parameters of EAST-NBI are reasonable, monitor the states of the experimental equipment in real time, storage the real-time data and make it easy to perform self-protection and alarm automatically. This design is related to many kinds of technologies, such as shared memory, multithreading, TCP protocol and so on.