The invention provides a method for measuring a strength index of interaction between converter stations of a multi-feed 
direct current system. The method comprises the following steps that (1)a multi-feed 
alternating current and 
direct current power grid receiving 
end system is taken as a research focus, 
direct current converter stations to be researched are determined, and it is assumed that the number of the direct current converter stations to be researched is N, and the direct current converter stations to be researched have three phases of A, B and C; (2) electromechanical transient 
simulation calculation is conducted on the 
power grid with electromechanical transient 
simulation software, a single-phase grounded 
short circuit with certain resistance is arranged at the phase A at a converter 
bus i, i=1, 2, ...N, the change of the 
voltage of the phase A at the converter 
bus i is observed, the grounded resistance of the 
short circuit is adjusted constantly, the 
voltage of the phase A at the converter 
bus i drops by 1% after the 
short circuit, the variation 
delta UAj of the 
voltage of the phase A at the converter bus j is recorded, j=1, 2, ..., i-1, i+1, ...N, and the calculation of the phase B and the calculation of the phase C are identical with that of the phase A; (3) a single-phase multi-feed 
interaction factor SMIIFij between the converter 
station i and the converter 
station j is calculated. By means of the method, references are provided for evaluating the strength of the interaction between all converter stations in the multi-feed direct current 
system in asymmetrical faults.