Abstract: The existing definition of the multi-infeed effective short circuit ratio（MIESCR） fails to depict the system strength of the multi-infeed system with rectifier stations integrated.To represent this feature,it should be modified.The dual-infeed HVDC test system with the rectifier station connected was established in the work.Based on the maximum power stability curve method,the new definition of multi-infeed effective short circuit ratio was proposed after conducting a range of parametric studies.Using the inverter/rectifier mixed triple-infeed systems in the critical stability and the transient overvoltage（TOV） calculation of the inverter,the effectiveness of the new MIESCR definition was verified.