Method of optimising the adjustment parameters of a braiding machine equipped with spindles, themselves provided with reels of braiding wires constituted by strands of a particular material for braiding a shielding sheath of a determined diameter on electrical conductor bundles, said adjustment parameters comprising a plurality of spindle groups, and a plurality of braiding wire groups, characterised in that: A/ in a first step I, for each diameter of electrical conductor bundles, a first set of spindle groups and of braiding wire groups is determined for which a range of the braiding angles is defined specifically for each wire, each range on the one hand being delimited by minimum braiding angles and maximum braiding angles comprised in a predetermined range of the braiding angles, and on the other hand corresponding to a predetermined maximum value (Ro) of the DC electrical resistance load per unit length and also to a predetermined minimum value of the optical coverage rate (Kc), B/ in a second step II, for each diameter of electrical conductor bundles and for each spindle group associated with each of the braiding wire groups among those of said first set, it is verified that the corresponding transfer impedance is, for each braiding angle comprised in said range, below a template representing the variation of an upper limit of the transfer impedance as a function of the frequencies of the electromagnetic radiation of conducted type, and a second set of spindle groups and of braiding wire groups comprised in said first set is selected, for which an optimum braiding angle corresponds to a minimum mass of the shielding sheath, C/ in a third step III, for each diameter of electrical conductor bundles, a single spindle group and a single braiding wire group is selected from those obtained in said second set as well as the corresponding single braiding angle so as to minimise the number of combinations of spindles groups and of braiding wire groups, a different combination being allocated to each different series of consecutive diameters of the electrical conductor bundles. A/ in a first step I, for each diameter of electrical conductor bundles, a first set of spindle groups and of braiding wire groups is determined for which a range of the braiding angles is defined specifically for each wire, each range on the one hand being delimited by minimum braiding angles and maximum braiding angles comprised in a predetermined range of the braiding angles, and on the other hand corresponding to a predetermined maximum value (Ro) of the DC electrical resistance load per unit length and also to a predetermined minimum value of the optical coverage rate (Kc), B/ in a second step II, for each diameter of electrical conductor bundles and for each spindle group associated with each of the braiding wire groups among those of said first set, it is verified that the corresponding transfer impedance is, for each braiding angle comprised in said range, below a template representing the variation of an upper limit of the transfer impedance as a function of the frequencies of the electromagnetic radiation of conducted type, and a second set of spindle groups and of braiding wire groups comprised in said first set is selected, for which an optimum braiding angle corresponds to a minimum mass of the shielding sheath, C/ in a third step III, for each diameter of electrical conductor bundles, a single spindle group and a single braiding wire group is selected from those obtained in said second set as well as the corresponding single braiding angle so as to minimise the number of combinations of spindles groups and of braiding wire groups, a different combination being allocated to each different series of consecutive diameters of the electrical conductor bundles.