HVDC systems are extensively utilized due to their numerous advantages. However, these systems encounter significant challenges in terms of transient voltage stability during fault occurrences. Therefore, there is a pressing need for an improved evaluation method to assess the transient voltage level in multi-infeed systems. To address this issue, this paper proposes a novel index, namely the transient multi-infeed short circuit ratio (TMSCR), based on the short circuit ratio (SCR) index, which takes into account the transient voltage characteristics of the system. The paper proceeds as follows: Firstly, it introduces the definition of existing indicators. Secondly, it incorporates transient active or reactive power to derive an index that considers the transient characteristics. Finally, it compares the characteristics of the two short-circuit ratio indexes, and the simulation results validate the accuracy of the proposed indicators.