Gigabar-grade cold-rolled high-strength steel and production method thereof

The invention discloses gigabar-grade cold-rolled high-strength steel and a production method thereof, and belongs to the technical field of high-strength steel production. The steel comprises the following chemical components in percentage by weight: 0.25 to 0.35 percent of C, 0.5 to 1.1 percent of Si, 2.2 to 2.9 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, 0.04 to 0.2 percent of Al, 0.6 to 1.2 percent of Si and Al, 0.35 to 0.6 percent of Cr, 0.12 to 0.24 percent of Mo, 0.08 to 0.2 percent of Cu, 0.002 to 0.0035 percent of B, less than or equal to 0.007 percent of Ca, one or two of Ti and Nb, 0.02 to 0.04 percent of Nb, 0.02 to 0.06 percent of Ti, less than or equal to 0.08 percent of Nb and less than or equal to 0.08 percent of Fe, and the balance of Fe and inevitable impurities. The production method comprises the procedures of smelting, continuous casting, hot rolling, cover annealing, acid rolling and continuous annealing. The high-strength steel has