The invention provides cold-rolling medium Mn steel with a low Mn content and a high product of strength and ductility, and a preparation method for the same. The steel contains, by weight, the chemical components including 0.15%-0.6% of C, 3.0%-6.0% of Mn, 1.0%-3.0% of Al, 0.0%-2.0% of Si, 0%-5.0% of Cr, 0%-2.0% of Ni and the balance being Fe and inevitable impurities. Preparation of the cold-rolling medium Mn steel with the high product of strength and ductility comprises the steps that molten steel is smelted by a converter, and a continuous casting blank is obtained through continuous casting; the continuous casting black is heated by a heating furnace, and a hot-rolling plate roll is obtained after hot rolling; the hot-rolling roll is treated with softening annealing by a bell furnace, and cold and hard belt steel is obtained after cold rolling; and the cold and hard belt steel is treated with continuous annealing, and the finished product of the cold-rolling medium Mn steel withthe high product of strength and ductility is obtained. The cold-rolling medium Mn steel and the preparation method provided by the invention have the beneficial effects that the Mn steel has the highproduct of strength and ductility on the premise that good ductility is ensured during cold rolling; and the significance of practical application is high.