The invention provides a method for preparing a steel cord with a strong breaking force and a twisting device. The method comprises the following steps of sequentially inserting 11 to-be-drawn monofilaments through n drawing dies in a water tank drawing machine to form 11 finished monofilaments, wherein the widths of the sizing tapes of the n drawing dies are sequentially decreased, and n is a positive integer smaller than 20; taking three finished monofilaments of the 11 finished monofilaments, and twisting the three finished monofilaments together in a first twisting direction and a first twisting distance at a twisting point to form a core strand; putting together the eight finished monofilaments other than the three finished monofilaments and the core strand, and deforming the eight finished monofilaments and the core strand jointly by a deforming device; knitting and twisting the deformed eight finished monofilaments on the outer circumference of the deformed core strand in a second twist direction and a second twist distance. By the method, the cementing rate of the steel cord can be increased, and the strength and breaking force of the steel cord can be improved by reducingthe wet draw times of the monofilaments and deforming the monofilaments.