With the gradual growth of the number and capacity of infeed DC, the characteristic of “strong DC and weak AC” in some receiving power grids have become prominent in China, and the operation patterns and stability attributes have become increasingly complex. This paper considers the adaptability of multi?in?feed HVDC power transmission systems under normal and fault operating conditions. It proposes a multi?dimensional evaluation index system for comprehensively evaluating the carrying capacity of main grid frame of a multi?in?feed HVDC power transmission system. This indicator system can be used to reveal the grid strength, anti?interference ability and resilience level of a multi?in?feed HVDC power transmission system under three operating scenarios: normal state, failure state and fault recovery process, to comprehensively evaluate the capacity to carry HVDC of main grid frame of multi?infeed HVDC power transmission system. Based on the Henan power grid planning data, an application empirical study was carried out, and the weak links that restricted the capacity to carry HVDC of Henan’s primary grid were evaluated. The countermeasures for improving the carrying ability of the primary grid were further given.