A cold-rolled annealed dual-phase steel is provided, having a microstructure of ferrite and martensite, and comprising the following chemical elements in mass percentage: 0.08% to 0.1% of C, 1.95% to 2.2% of Mn, 0.1% to 0.6% of Si, 0.020% to 0.050% of Nb, 0.020% to 0.050% of Ti, 0.015% to 0.045% of Als, 0.40% to 0.60% of Cr, 0.2% to 0.4% of Mo, 0.001% to 0.005% of Ca, and the balance being Fe and other inevitable impurities. A method for manufacturing the cold-rolled annealed dual-phase steel is also provided, comprising the steps of: (1) smelting and casting; (2) hot rolling; (3) cold rolling; (4) annealing; and (5) temper rolling.