A magnetic particle, comprising: a core, the core comprising an inorganic magnetic particle, the inorganic magnetic particle comprising a metal oxide; and a shell, the shell comprising an organic material; wherein: the organic material is coated on a surface of the inorganic magnetic particle; the inorganic magnetic particle and the organic material are linked to form a core-shell structure; and the core has a diameter in the range of from 2 nm to 20 μm, characterized in that: the inorganic magnetic particle is a ferrite having a general chemical formula of XFe 2 O 4, X represents a divalent iron ion (Fe 2+), or represents a divalent metal ion selected from the group consisting of Mn 2+, Zn 2+, Cu 2+, Ni 2+, Mg 2+, and Co 2+, or represents a divalent metal ion mixture comprising Ni-Zn and Mn-Mg-Zn; or the inorganic magnetic particle is an iron oxide; or the inorganic magnetic particle is a mixture of the ferrite, iron oxide, metallic iron, and iron nitride; the organic material is an organic compound comprising an amine group, wherein the organic compound comprising the amine group comprises an aliphatic amine, an alkanolamine, an amide, an alicyclic amine, an aromatic amine, a naphthylamine, or derivatives thereof; or the organic material is an organic polymer comprising an amine group; or the organic material is a mixture of the organic compound comprising the amine group and the organic polymer comprising the amine group; and the inorganic magnetic particle and the organic material are linked through a strong chemical bond to form the core-shell structure, and the strong chemical bond is a covalent bond between a metal atom in the inorganic magnetic particle and a nitrogen atom in the organic material. a core, the core comprising an inorganic magnetic particle, the inorganic magnetic particle comprising a metal oxide; and a shell, the shell comprising an organic material; the organic material is coated on a surface of the inorganic magnetic particle; the inorganic magnetic particle and the organic material are linked to form a core-shell structure; and the core has a diameter in the range of from 2 nm to 20 μm, the inorganic magnetic particle is a ferrite having a general chemical formula of XFe 2 O 4, X represents a divalent iron ion (Fe 2+), or represents a divalent metal ion selected from the group consisting of Mn 2+, Zn 2+, Cu 2+, Ni 2+, Mg 2+, and Co 2+, or represents a divalent metal ion mixture comprising Ni-Zn and Mn-Mg-Zn; or the inorganic magnetic particle is an iron oxide; or the inorganic magnetic particle is a mixture of the ferrite, iron oxide, metallic iron, and iron nitride; the organic material is an organic compound comprising an amine group, wherein the organic compound comprising the amine group comprises an aliphatic amine, an alkanolamine, an amide, an alicyclic amine, an aromatic amine, a naphthylamine, or derivatives thereof; or the organic material is an organic polymer comprising an amine group; or the organic material is a mixture of the organic compound comprising the amine group and the organic polymer comprising the amine group; and the inorganic magnetic particle and the organic material are linked through a strong chemical bond to form the core-shell structure, and the strong chemical bond is a covalent bond between a metal atom in the inorganic magnetic particle and a nitrogen atom in the organic material.