The invention relates to the field of third-generation advanced high-strength steel used for automobiles and discloses 1180 MPa-grade ultrahigh-strength low-cost cold-rolled quenched partition steel and a manufacturing method thereof. A steel plate comprises the chemical components including, by mass percent, 0.18-0.22% of C, 1.0-3.0% of Mn, 1.0-2.0% of Si, not greater than 0.05% of P, not greaterthan 0.02% of S, 0-0.05% of Nb, 0-0.2% of Ti and the balance iron and inevitable impurities. The steel plate manufacturing method relates to the process of steel smelting, hot rolling, cold rolling,pre-quenching and heat treatment, and finally, a ferrite-bainite-martensite-retained austenite mixed structure is obtained. According to the 1180 MPa-grade ultrahigh-strength low-cost cold-rolled quenched partition steel and the manufacturing method thereof, on the basis of traditional C-Mn-Si series quenched partition steel, Nb and Ti elements are added for refining the structure, pre-quenching treatment and a one-step partition process are adopted, finally the ultrahigh-strength quenched partition steel with the yield strength being 500-800 MPa, the tensile strength not smaller than 1180 MPa, the elongation after fracture not smaller than 20% and the product of strength and elongation not smaller than 24GPa.% is obtained, and the mechanical property is quite excellent.