PURPOSE: To precisely control a target coiling temp. with reduced computing quantity in the case a passing speed is rapidly changed in coiling a rolled sheet by a coiler.

CONSTITUTION: When a rolled sheet finished by hot rolling process is introduced into a cooling equipment and is coiled to the prescribed coiling device while pouring cooling water to rolled sheet, while a pouring quantity (pouring distance) is estimated, at a virtual cut sheet of the prescribed length set to rolled sheet, based on the measured temp. at the outlet side of finish rolling mill and the passing speed set beforehand, the water pouring to virtual cut sheet is executed. The water pouring quantity 6 for the virtual cut sheet, in which a passing speed 1 is accelerated in linear like B, is in a simple way set to the value linearly increasing/decreasing, an error 7 from the target temp. generated as a result is compensated to the adjusting zone arranged at the latter part of cooling equipment.