In order to quantitatively characterize the network invulnerability in the case of edge failure,the concept of mixed edge neighbor tenacity was proposed.The parameter calculation formulas of several types of graphs and the best possible upper and lower bounds were given,and the extreme value problem of this parameter was studied by combinatorial optimization method.By compar-ing the discrimination degrees of several types of edge neighbor invulnerability parameters,it is shown that the mixed edge neighbor tenacity is more accurate to characterize the invulnerability of some networks.