The invention discloses high-carbon cold-rolled automobile diaphragm spring steel. The high-carbon cold-rolled automobile diaphragm spring steel is prepared from the following constituents in percentage by weight: 0.70-0.90% of C, 0.15-0.35% of Si, 0.50-1.00% of Mn, P smaller than or equal to 0.008%, S smaller than or equal to 0.002%, 0.010-0.030% of Alt, 0.10-0.30% of V, 1.20-2.00% of Cr, 1.20-2.00% of Ni, 0.002-0.006% of Ca, and N smaller than or equal to 0.004%, and is prepared by the following production steps: molten iron desulphurization, smelting in a converter, refining in an LF (Ladle Furnace) furnace, processing in a RH vacuum furnace, continuous casting to form blanks, pit type slow cooling after cutting of cast blanks, cast blank heating, segmented hot rolling, reeling, slow cooling, annealing after cutting, cold rolling, quenching, tempering, and inspection for standby. The steel disclosed by the invention is rolled and thermally treated to achieve high strength, high elasticity, high limit of yielding, high fatigue limit resistance, low-temperature toughness and longer service life, and can be used for manufacturing various vehicle clutch assemblies, especially the large engineering machinery at the low temperature environment.