A method for producing a molded article, comprising the steps of: preparing a first steel plate and a second steel plate, wherein the second steel plate is prepared by a method including the steps of: reheating a steel slab, containing 0.04-0.06 wt% of carbon, 0.2-0.4 wt% of silicon (Si), 1.6-2.0 wt% of manganese (Mn), more than 0 wt% but not more than 0.018 wt% of phosphorus, more than 0 wt% but not more than 0.003 wt% of sulfur, 0.1-0.3 wt% of chromium (Cr), 0.0009-0.0011 wt% of boron, 0.01-0.03 wt% of titanium (Ti), 0.04-0.06 wt% of niobium (Nb), and a balance of iron (Fe) and unavoidable impurities, at a temperature between 1,200°C and 1,250°C; hot-rolling the reheated steel slab; coiling the hot-rolled steel slab to prepare a hot-rolled coil; uncoiling the hot-rolled coil, followed by cold rolling, thereby preparing a cold-rolled steel plate; and annealing the cold-rolled steel plate; joining the first steel plate and the second steel plate to each other, thereby preparing a joined steel plate; heating the joined steel plate at a temperature between 910°C and 950°C; subjecting the heated joined steel plate to hot-press molding, thereby preparing an intermediate molded article, wherein the hot-press molding comprises transferring the heated joined steel plate to a hot-press mold within 5-20 seconds; and cooling the intermediate molded article, wherein the first steel plate has a tensile strength higher than that of the second steel plate. preparing a first steel plate and a second steel plate, wherein the second steel plate is prepared by a method including the steps of: reheating a steel slab, containing 0.04-0.06 wt% of carbon, 0.2-0.4 wt% of silicon (Si), 1.6-2.0 wt% of manganese (Mn), more than 0 wt% but not more than 0.018 wt% of phosphorus, more than 0 wt% but not more than 0.003 wt% of sulfur, 0.1-0.3 wt% of chromium (Cr), 0.0009-0.0011 wt% of boron, 0.01-0.03 wt% of titanium (Ti), 0.04-0.06 wt% of niobium (Nb), and a balance of iron (Fe) and unavoidable impurities, at a temperature between 1,200°C and 1,250°C; hot-rolling the reheated steel slab; coiling the hot-rolled steel slab to prepare a hot-rolled coil; uncoiling the hot-rolled coil, followed by cold rolling, thereby preparing a cold-rolled steel plate; and annealing the cold-rolled steel plate; reheating a steel slab, containing 0.04-0.06 wt% of carbon, 0.2-0.4 wt% of silicon (Si), 1.6-2.0 wt% of manganese (Mn), more than 0 wt% but not more than 0.018 wt% of phosphorus, more than 0 wt% but not more than 0.003 wt% of sulfur, 0.1-0.3 wt% of chromium (Cr), 0.0009-0.0011 wt% of boron, 0.01-0.03 wt% of titanium (Ti), 0.04-0.06 wt% of niobium (Nb), and a balance of iron (Fe) and unavoidable impurities, at a temperature between 1,200°C and 1,250°C; hot-rolling the reheated steel slab; coiling the hot-rolled steel slab to prepare a hot-rolled coil; uncoiling the hot-rolled coil, followed by cold rolling, thereby preparing a cold-rolled steel plate; and annealing the cold-rolled steel plate; joining the first steel plate and the second steel plate to each other, thereby preparing a joined steel plate; heating the joined steel plate at a temperature between 910°C and 950°C; subjecting the heated joined steel plate to hot-press molding, thereby preparing an intermediate molded article, wherein the hot-press molding comprises transferring the heated joined steel plate to a hot-press mold within 5-20 seconds; and cooling the intermediate molded article, wherein the first steel plate has a tensile strength higher than that of the second steel plate.