The invention discloses high-plasticity dual-phase steel and a production method thereof. The high-plasticity dual-phase steel comprises the following chemical components in percentage by mass: 0.17 to 0.23 percent of C, 0.17 to 0.37 percent of Si, 0.50 to 0.80 percent of Mn, less than or equal to 0.020 percent of P, less than or equal to 0.005 percent of S, 0.70 to 0.95 percent of Cr, 0.015 to 0.025 percent of Al, 0.010 to 0.020 percent of Ti, less than or equal to 0.02 percent of Ni, less than or equal to 0.05 percent of Cu, less than or equal to 0.005 percent of Mo, 0.0015 to 0.0018 percent of O and the balance Fe and inevitable impurities. The production method of the high-plasticity dual-phase steel comprises the following steps of converter smelting, argon station treatment, LF refining, continuous casting, rolling and cooling. According to the steel, a proper amount of Ti and Al alloy is added to conduct microalloying on the steel, the quality of molten steel is further purified, and by means of the characteristics of the Ti alloy and the characteristic that a separated Ti-containing compound can effectively hinder grain coarsening, the prepared steel has the diameter phi of 24-100 mm, the yield strength of 850-1000 MPa, the tensile strength of 1000-1150 MPa, the ductility of 14-17.5%, the percentage reduction of area of 44.5-48% and the impact energy of 60-75 J; and the hardenability and plasticity index of the steel are greatly improved.