The invention relates to automotive cold-rolled diaphragm spring steel and a production method thereof. The automotive cold-rolled diaphragm spring steel comprises the following components by weight percentage: C of 0.40-0.65, Si of 0.15-0.35, Mn of 0.60-1.00, P of less than or equal to 0.010. S of less than or equal to 0.007, Alt of less than or equal to 0.040, Ni of 0.20-0.50, Cr of 0.80-1.20, V of 0.27-0.55 and N of less than or equal to 0.005, and a tempered sorbite body is adopted as a control metallographic structure. The process comprises the steps of: desulphurization, smelting, refining, vacuum processing, continuous casting into a billet, thermal insulation in segments according to the temperature, heating of the cast billet, rolling, coiling, slow cooling, cutting, first annealing, first cold rolling, second annealing, second cold rolling, formation, quenching, tempering and preparation for use. The automotive cold-rolled diaphragm spring steel has excellent comprehensive mechanical properties. Difficulties in cutting and cold rolling can be reduced due to annealing, a tempered martensite structure is obtained due to heat treatment of quenching and tempering, and sufficient strength and wear resistance of the steel can be ensured due to composite reinforcing effects of micro-alloys such as Cr, Ni and V in the steel.