A method for manufacturing an oriented silicon steel product with high magnetic-flux density comprising the following steps: 1) smelting and casting, wherein the oriented silicon steel is composed of, by weight, 0.035∼0.065% of C, 2.9∼4.0% of Si, 0.05∼0.20% of Mn, 0.005∼0.01% of S, 0.015∼0.035% of Al, 0.004∼0.009% of N, 0.005∼0.090% of Sn, 0.200∼0.800% of Nb, the rest being Fe and unavoidable inclusions; and after being smelted via a rotary furnace or an electric furnace, molten steel is secondarily refined and then casted into steel slabs; 2) hot rolling, wherein said steel slabs are heated in a heating furnace to 1090∼1200 °C, and then, are hot rolled into steel plates at a beginning temperature of 1180°C and are finished with the hot rolling step at a finishing temperature of 860°C, said steel plates are cooled by laminar flow of water to below 650°C and then coiled into coiled-shape plates; 3) normalizing, wherein said coiled-shape plates are normalized at the normalization temperature of 1050∼1180 °C for 1∼20sec and at the normalization temperature of 850∼950 °C for 30∼200sec, and are immediately thereafter cooled down at a cooling rate of 10∼60°C/sec; 4) cold rolling, wherein after being normalized, said steel plates are cold rolled into steel sheets with a thickness of a finished sheet at a rolling compression ratio not less than 75%; 5) decarburization annealing, wherein said steel sheets are decarburized to a temperature of 800∼860°C at a temperature rise rate of 15∼35°C/sec and maintained at the temperature for 90∼160sec; 6) MgO coating wherein said steel sheets are covered with a coating which is composed of, by weight, 0.1∼10% of NH 4 Cl and 0.5∼30% of P 3 N 5, and MgO as the rest component where the MgO is a main component; 7) high temperature annealing wherein said steel sheets are firstly heated to a temperature of 700∼900°C, and then secondarily heated to 1200°C at a secondary temperature rise rate of 9∼17°C/hr and maintained at 1200°C for 20hr for being purification annealed; 8) coating an insulation layer wherein the surfaces of the steel sheets which have gone through the high temperature annealing are coated with an insulation layer, and then a finished oriented silicon steel product with high magnetic-flux density with premium magnetic property is obtained after hot drawing, tempering and annealing. 1) smelting and casting, wherein the oriented silicon steel is composed of, by weight, 0.035∼0.065% of C, 2.9∼4.0% of Si, 0.05∼0.20% of Mn, 0.005∼0.01% of S, 0.015∼0.035% of Al, 0.004∼0.009% of N, 0.005∼0.090% of Sn, 0.200∼0.800% of Nb, the rest being Fe and unavoidable inclusions; and after being smelted via a rotary furnace or an electric furnace, molten steel is secondarily refined and then casted into steel slabs; 2) hot rolling, wherein said steel slabs are heated in a heating furnace to 1090∼1200 °C, and then, are hot rolled into steel plates at a beginning temperature of 1180°C and are finished with the hot rolling step at a finishing temperature of 860°C, said steel plates are cooled by laminar flow of water to below 650°C and then coiled into coiled-shape plates; 3) normalizing, wherein said coiled-shape plates are normalized at the normalization temperature of 1050∼1180 °C for 1∼20sec and at the normalization temperature of 850∼950 °C for 30∼200sec, and are immediately thereafter cooled down at a cooling rate of 10∼60°C/sec; 4) cold rolling, wherein after being normalized, said steel plates are cold rolled into steel sheets with a thickness of a finished sheet at a rolling compression ratio not less than 75%; 5) decarburization annealing, wherein said steel sheets are decarburized to a temperature of 800∼860°C at a temperature rise rate of 15∼35°C/sec and maintained at the temperature for 90∼160sec; 6) MgO coating wherein said steel sheets are covered with a coating which is composed of, by weight, 0.1∼10% of NH 4 Cl and 0.5∼30% of P 3 N 5, and MgO as the rest component where the MgO is a main component; 7) high temperature annealing wherein said steel sheets are firstly heated to a temperature of 700∼900°C, and then secondarily heated to 1200°C at a secondary temperature rise rate of 9∼17°C/hr and maintained at 1200°C for 20hr for being purification annealed; 8) coating an insulation layer wherein the surfaces of the steel sheets which have gone through the high temperature annealing are coated with an insulation layer, and then a finished oriented silicon steel product with high magnetic-flux density with premium magnetic property is obtained after hot drawing, tempering and annealing.