The invention discloses a hot milling steel plate with low cost and a production method thereof. The hot milling steel plate comprises the following chemical ingredients in percentage by weight: 0.10 to 0.22 percent of C, at most 0.35 percent of Si, 0.60 to 0.80 percent of Mn, at most 0.025 percent of P, at most 0.025 percent of S and the balance of Fe and unavoidable impurity elements. The method comprises the following steps: using a conventional continuous casting method for casting the hot milling steel plate into a continuous casting plate blank with the thickness of 200 mm; heating the continuous plate blank to 1150 to 1200 DEG G for coarse milling, wherein the thickness of the middle plate blank after the coarse milling is between 30 mm and 36 mm; using a core-free conveying hot coiling box for coiling; controlling the final rolling temperature in a range between 830 and 870 DEG C; cooling the plate blank to 650 to 700 DEG C at a cooling speed between 40 and 50 DEG C/s after the fine milling; then, cooling the plate blank to a temperature range between 540 and 580 DEG C through a layer flow cooling at the cooling speed between 10 and 20 DEG C/s; and carrying out coiling. The Q345 low-alloy high-intensity hot milling steel plate produced by the method has the characteristics of low cost, stable mechanical property, good toughness matching performance and the like.