Abstract: Belo Monte ultra high-voltage direct current（UHVDC） projects in Brazil are double-circuit DC transmission projects.The double-circuit DC projects belong to different project companies with no unified design, phased construction and separate management. Different equipment suppliers have different design concepts. To solve the above problems, the main control system is designed, and an active power control coordination strategy for double-circuit DC projects is proposed, which could achieve mutual support for the double-circuit DC power and facilitate stable operation of the power grid. Considering the reactive power control of double-circuit DC projects both use the constant AC voltage control strategy, a coordinated control strategy for doublecircuit AC filters is proposed. In the case where the double-circuit AC filters are controlled independently, orderly switching can be achieved. Aiming at the operation mode of the double-circuit DC projects sharing ground electrodes in Xingu converter station, the corresponding control and protection strategies are proposed to meet the needs of the double-circuit DC projects sharing the common ground electrodes. Through the joint test and on-site operation, the effectiveness of the design scheme is verified.