As the development of mine, oil and gas resources exploitation in the ocean, the underwater equipments work more and more deeply. With the support of the Chinese high technology develop program (the 863 program), we study and design a new underwater 3500m electrical driven manipulator. The manipulator features modular integration joints, open architecture and simple centralized control system. The working system design is discussed in detail. Experiments results demonstrated the manipulator work ability. It can be mounted on working class remotely operated vehicles (ROVs) or Autonomous underwater vehicle (AUVs).