With the further advance of the rapid social and economic development and the power transmission from west to east, Guangdong power grid HVDC is gradually intensive, resulting in a series of problems, such as HVDC interaction intensified, end system voltage supporting ability is insufficient, the system stability becomes worse, and putting forward the new challenge to the power system planning and operation. To fundamentally solve a series of safety and stability problems above, this paper introduces the multi infeed MISCR concept based on the CIGRE DC working groups. Through the integrity, balance, interference and comprehensiveness indicators to measure the interaction of multiple HVDC, it presents a comprehensive comparison method considering interaction between multiple DC stability, economic effect quantitative comparison of evaluation indicators, which has the operational characteristics of the DC optimal placement, can adapt to multi DC concentrated feed in Guangdong power grid, and improve power system stability.