The invention relates to a method of performing electrochemical corrosion with the help of a silicon-based three-dimensional structure magnetic field. The method comprises the following steps: performing photoetching of a silicon wafer, preparing corrosive liquid, preparing for electrochemical corrosion, performing electrochemical corrosion and performing after-treatment, wherein when the corrosive liquid is prepared, hydrofluoric acid, dimethylformamide and water in the volume ratio of (2.5-3.5):(14-18):1 are mixed to be used as negative electrode corrosive liquid and analytically pure NH4F with the mass concentration of 96%, HF with the mass concentration of 40% and water in the volume ratio of 3:6:10 are mixed to prepare hydrofluoric acid buffer corrosive liquid used as positive electrode corrosive liquid; and during the preparation of the magnetic field, the direction of the magnetic field is perpendicular to (100) crystallographic orientation and also perpendicular to the direction of the electric field, and the direction of the magnetic field is used as x axis. The method of the invention has the advantages of simple technology, high practicability, easy implementation and the like, and the product with silicon-based three-dimensional structure of large-distance steep graphs.