The invention relates to an installation of metallurgy industry rolling mills, pinch pass mill, burnishing machines and the like large-scale mechanical equipment, especially to an installation method of a large-scale rolling mill, which is characterized in that the installation of a large-scale rolling mill is realized by the process steps of base preparation, rolling mills bearing plate installation, rolling mills motherboard transverse alignment, sling preparation, memorial archway transverse alignment, memorial archway check-up, roll-changer installation and rolling mill accessory installation. The invention satisfies all requirement of different construction sites, effectively resolves hanging difficult problem, saves work efficiency about 6-7 times, ensures installation quality, uses hydraulic bolt stretchers to avoid bolt up force moment from macrolesion bolt, and adopts small fastening force moment to allow rolling mills subbase to become flexible. Work difference bands are used to control the roll changing transmission device central line and the rolling mill central line to ensure installation quality. According to combination of calculation and on-site practicality, the invention not only can be used for rolling mills installation, but also can spread in mechanical equipment installation with common advising signification.