CiADS is a science researching facility, which destination is about energy Providence. The control system of CiADS will have more than hundred types of device, and include more than thousand equipment and sensors. Based on the background of researching and energy project, the control system should overcome two challenges. First is that building a open architecture to face the flexibility of changed requirement. the second is that the flexibility should as less as possible influence the checking result of nuclear law and standard by authority. To meet the requirement, the control system will be divided into 3 levels. Level 2 will provide the OPI, data analysis interface and simulation to all users. Level 1 provides implement of control and security logic. Meantime it will provide an engine and interface for collection and package of some reconstructed data. Level 0 will implement the local control and provide all data and information to other levels. The paper mainly introduces the architecture and some works to build the control system to make it to overcome the two challenges.