The invention discloses thin-gauge cold-rolled annealed ultra-high-strength steel and a production method thereof. The ultra-high-strength steel comprises the following chemical components by mass: 0.15 to 0.25% of C, 1.8 to 2.6% of Mn, 0.6 to 1.2% of Si, no more than 0.010% of S, no more than 0.020% of P, 0.030 to 0.060% of Als, 0.30 to 0.60% of Cr and no more than 0.006% of N, with the balance being Fe and unavoidable impurities. The production method comprises the primary cold rolling, cover annealing, secondary cold rolling and continuous annealing procedures of hot-rolled strip steel. According to the invention, expensive alloying elements are not added for improving and homogenizing a structure; the produced steel has good elongation at break and bending performance; and compared with a conventional dual-phase steel production process, the production method has the advantages that requirements on the capacity of equipment are low in each procedure, production process is stable, product yield is high and the production of ultra-high-strength thin-gauge products can be realized.