A manufacturing method of corrosion resistant mirror die steel, characterized by comprising the following steps: smelting into molten steel, casting into billets, pre-forging annealing, forging, post-forging annealing, and heat treating; wherein, the molten steel consists of the following chemical components in percentage by weight: 0.35%-0.45% of C, 12%-15% of Cr, Co≤0.05%, 0.4%-0.7% of Mn, 0.35%-0.55% of Si, 0.08%-0.20% of Mo, 0.10%-0.30% of Ni, 0.08%-0.30% of W, 0.10%-0.30% of V, 0.01-0.05% of Ti, P≤0.020%, S≤0.012%, and the balance of Fe; the heat treating comprises the following steps: heating to 1,120 °C-1,200 °C, holding for 12-20 h, quenching, and tempering at 500-590 °C for 5-20 h, wherein the quenching comprises the following steps: discharging, air cooling for 2-3 min, spray cooling for 3-5 min, water cooling to the surface temperature of 690-710 °C, air cooling for 3-5 min, proceeding to water cooling to the surface temperature of 390-410 °C, air cooling for 3-5 min, proceeding to water cooling to the surface temperature of 190-210 °C, and removing from the heat treatment tank for air cooling, and the spray cooling pressure is 5-8 MPa; the water cooling pressure is 7-16 MPa; the air cooling speed is 2-4 m/s; the casting comprises the step of obtaining steel ingots by die casting, wherein the die casting adopt bottom pouring with argon gas protection at the casting nozzle; electroslag remelting is performed on the billets and the slag system used for the electroslag remelting comprises CaF 2, CaO, Al 2 O 3, MgO and SiO 2, wherein the slag system comprises the following components in parts by weight: 50 parts of CaF 2, 30 parts of CaO, 10 parts of Al 2 O 3, 5 parts of MgO and 5 parts of SiO 2; the heating temperature is not less than 1,200 °C, and the holding time is 12-15 h in the pre-forging annealing step; the heating temperature is 1230-1250 °C in the forging step, and the billets are forged into the specifications with thickness of 300-600 mm, width of 800-1350 mm, length of being more than 3000mm, and total rolling deformation of 60-80%; and the post-forging annealing step comprises the following sub-steps: heating the forged module to 600-650 °C, holding for 4-8 h, furnace cooling to 280-350 °C, holding for 2-6 h, heating to 650-700 °C, holding for 25-35 h, cooling to 390-410 °C at 30-60 °C/h, and cooling to 140-160°C at 15-20 °C/h. the molten steel consists of the following chemical components in percentage by weight: 0.35%-0.45% of C, 12%-15% of Cr, Co≤0.05%, 0.4%-0.7% of Mn, 0.35%-0.55% of Si, 0.08%-0.20% of Mo, 0.10%-0.30% of Ni, 0.08%-0.30% of W, 0.10%-0.30% of V, 0.01-0.05% of Ti, P≤0.020%, S≤0.012%, and the balance of Fe; the heat treating comprises the following steps: heating to 1,120 °C-1,200 °C, holding for 12-20 h, quenching, and tempering at 500-590 °C for 5-20 h, wherein the quenching comprises the following steps: discharging, air cooling for 2-3 min, spray cooling for 3-5 min, water cooling to the surface temperature of 690-710 °C, air cooling for 3-5 min, proceeding to water cooling to the surface temperature of 390-410 °C, air cooling for 3-5 min, proceeding to water cooling to the surface temperature of 190-210 °C, and removing from the heat treatment tank for air cooling, and the spray cooling pressure is 5-8 MPa; the water cooling pressure is 7-16 MPa; the air cooling speed is 2-4 m/s; the casting comprises the step of obtaining steel ingots by die casting, wherein the die casting adopt bottom pouring with argon gas protection at the casting nozzle; electroslag remelting is performed on the billets and the slag system used for the electroslag remelting comprises CaF 2, CaO, Al 2 O 3, MgO and SiO 2, wherein the slag system comprises the following components in parts by weight: 50 parts of CaF 2, 30 parts of CaO, 10 parts of Al 2 O 3, 5 parts of MgO and 5 parts of SiO 2; the heating temperature is not less than 1,200 °C, and the holding time is 12-15 h in the pre-forging annealing step; the heating temperature is 1230-1250 °C in the forging step, and the billets are forged into the specifications with thickness of 300-600 mm, width of 800-1350 mm, length of being more than 3000mm, and total rolling deformation of 60-80%; and