To effectively control an edge drop while preventing deterioration in a profile when cold-rolling a sheet for a plating sheet.

The following numerical formula models are previously prepared: a numerical formula model that expresses edge drops on the outlet side of the final stand by taking, as variables, a rolling load, controlled variables of a profile controlling means, and edge drops of a base stock before rolling respectively at each stand of a tandem rolling mill; and a numerical formula model that expresses elongation percentage differences of points, positioned at given distances from the sheet end, against the sheet-width center on the outlet side of each stand from a 1st stand to the stand one step before the final one by taking, as variables, controlled variables of the profile controlling means, a rolling load, and edge drops of the base stock before rolling at each stand up to the relevant stand. The rolling load and the edge drops of the base stock before rolling at each stand are continuously measured and substituted in the numeral formula models. The variables of the profile controlling means at a plurality of stands among from the 1st stand to the stand one step before the final one are constantly corrected so that the edge drops on the outlet side of the final stand coincide with target values within the range where the elongation percentage differences do not exceed a limit value.