The invention relates to a high-strength low-alloy hot-dip aluminized and galvanized steel strip and a production method thereof. The hot-dip aluminized and galvanized steel strip comprises a steel base plate and an alloy coating, wherein the steel base plate comprises the following chemical components in percentage by weight: 0.02-0.10% of C, 0.5-1.2% of Mn, 0.01-0.07% of P, 0.01-0.12% of Nb, less than or equal to 0.0080% of N, less than or equal to 0.02% of S and the balance of Fe and inevitable impurities, wherein Nb-0.22C-1.1N is equal to or greater than 0.01% and less than or equal to 0.1% and Mn / 1.7S is equal to or greater than 8; the alloy coating comprises the following chemical components in percentage by weight: 50-58% of Al, 40-45% of Zn, 1.0-2.0% of Si, 0.005-0.020% of Ti and the balance of unavoidable impurities. According to the hot-dip aluminized and galvanized steel strip, by virtue of smelting, casting, carrying out hot rolling and cold rolling, continuously annealing and carrying out hot-dip aluminizing and galvanizing, the aluminum-zinc coating is evenly and densely adhered to the steel base plate, the obtained low-alloy hot-dip aluminized and galvanized steel strip has the yield strength of 410-570MPa, the tensile strength equal to or greater than 470MPa and elongation equal to or greater than 15% and has both good strength and toughness and excellent corrosion resistance. The production process is low in cost and high in steel plate yield.