A manufacturing method of an oriented silicon steel, comprising the following steps in sequence: heating a slab of the oriented silicon steel to 1100-1200°C and then performing a hot rolling to obtain a hot rolled plate; before cold rolling, performing an annealing treatment for hot rolled plate on the hot rolled plate, wherein the annealing treatment for hot rolled plate is performed at an annealing temperature of 900-1150°C and an annealing cooling rate of 20-100°C/s; performing a cold rolling on the hot rolled plate at a cold rolling reduction ratio of 85% or more, so as to obtain a cold rolled plate having a thickness of a finished product of the oriented silicon steel; performing an annealing treatment on the cold rolled plate to obtain the finished product of the oriented silicon steel, wherein the annealing treatment on the cold rolled plate comprises the following in sequence: decarbonization annealing, coating an annealing separator, high-temperature annealing, applying an insulating coating, and hot-stretching leveling annealing; wherein the manufacturing method further comprises: before the high-temperature annealing, performing a nitriding treatment on the cold rolled plate; wherein the slab of the oriented silicon steel comprises the following components by weight percentage: 2.5-4.0% of Si, 0.010-0.040% of acid-soluble aluminum Als, 0.004-0.012% of N, 0.015% or less of S, 0.050-0.075% of C, and 0.08-0.14% of Mn and a balance of Fe and inevitable impurities, and an area ratio of small crystal grains having a grain size of less than 5 mm in the finished product of the oriented silicon steel is not more than 3%, and a ratio μ17/μ15 of a magnetic conductivity under magnetic induction of 1.7T to a magnetic conductivity under magnetic induction of 1.5T in the finished product of the oriented silicon steel is 0.50 or more. heating a slab of the oriented silicon steel to 1100-1200°C and then performing a hot rolling to obtain a hot rolled plate; before cold rolling, performing an annealing treatment for hot rolled plate on the hot rolled plate, wherein the annealing treatment for hot rolled plate is performed at an annealing temperature of 900-1150°C and an annealing cooling rate of 20-100°C/s; performing a cold rolling on the hot rolled plate at a cold rolling reduction ratio of 85% or more, so as to obtain a cold rolled plate having a thickness of a finished product of the oriented silicon steel; performing an annealing treatment on the cold rolled plate to obtain the finished product of the oriented silicon steel, wherein the annealing treatment on the cold rolled plate comprises the following in sequence: decarbonization annealing, coating an annealing separator, high-temperature annealing, applying an insulating coating, and hot-stretching leveling annealing; wherein the manufacturing method further comprises: before the high-temperature annealing, performing a nitriding treatment on the cold rolled plate; wherein the slab of the oriented silicon steel comprises the following components by weight percentage: 2.5-4.0% of Si, 0.010-0.040% of acid-soluble aluminum Als, 0.004-0.012% of N, 0.015% or less of S, 0.050-0.075% of C, and 0.08-0.14% of Mn and a balance of Fe and inevitable impurities, and an area ratio of small crystal grains having a grain size of less than 5 mm in the finished product of the oriented silicon steel is not more than 3%, and a ratio μ17/μ15 of a magnetic conductivity under magnetic induction of 1.7T to a magnetic conductivity under magnetic induction of 1.5T in the finished product of the oriented silicon steel is 0.50 or more.