The invention discloses a rolling method for large-broadening-ratio wide and heavy steel plates. The broadening ratio is not lower than 1.75; and the method comprises the following steps: after right-angled continuous casting blanks are heated and descaled, vertical-horizontal rollers are used for longitudinal pre-forming rolling, so that foot roll indentation lines on narrow surfaces of the continuous casting blanks are overturned onto the upper and lower surfaces through broadening; then, steel is turned for transverse broadening rolling; and after broadening, the steel is turned again for longitudinal forming rolling. Compared with a traditional rolling mode for wide and heavy plates, the rolling method changes the stress state and the flowing condition of the foot roll indentation lines on the narrow surfaces, effectively prevents or relieves the edge straight cracking defect caused by the indentation lines, and improves the yield of wide steel plates.