The invention relates to a method for adding scrap steel to a blast furnace to produce molten iron, which mainly includes the steps of mixing materials, distributing materials, smelting, reforming iron trenches, distributing iron trenches, distributing molten iron tanks, baking the molten iron tanks, tapping and the like. In the present invention, steel scrap is added in different ways at different times during the blast furnace smelting process, which shortens the overall smelting time, increases the amount of iron tapping, and greatly saves the amount of coke used, and improves the straightness of the blast furnace, etc. technical effect. Adopting the method of the invention can greatly improve the utilization rate of scrap steel, digest more industrial and domestic waste steel, reduce energy consumption, reduce the discharge of harmful substances, meet the development requirements of environmental protection and energy saving, and have important social benefits while increasing the economic benefits of blast furnaces. benefit.