Object To provide a method for producing a bis-quaternary ammonium salt efficiently and a novel synthetic intermediate thereof.Solution The present invention relates to a method for producing a bis-quaternary ammonium salt represented by a general formula [3] which comprises reacting a disulfonic acid ester represented by a general formula [1] (in the formula, definitions of two R1's and T are as described in claim 1) with a tertiary amine represented by a general formula [2] (in the formula, definitions of R3 to R5 are as described in claim 1), and a disulfonic acid ester represented by a general formula [1′] (in the formula, two R16's represent independently a halogen atom or a C1-C3 fluoroalkyl group, and two m's represent independently an integer of 1 to 5).