The invention relates to one-component aqueous self-crosslinking acrylic polyurethane core-shell emulsion. The emulsion is characterized in that different acrylic monomers are selected for polymerization to prepare a core structure with better physical performance, post-crosslinking monomers such as diacetone acrylamide and adipic acid dihydrazide are introduced in the preparation process of an acrylic core, then polyhydroxy monomers containing carboxyl groups are introduced into polyurethane segments and correspondingly introduced into the acrylic core structure by means of a free radical mode, the hydrophilicity and stability of the emulsion are further improved by acid-base salt formation, and the emulsion with acrylic acid as the core and polyurethane as a shell is prepared. In the film formation process of the emulsion, as volatile ammonia volatilizes, the system gradually becomes acidic, and the post-crosslinking monomers are subjected to a crosslinking reaction, so that the crosslinking density of the paint film is further increased, and therefore the physical and mechanical properties, chemical resistance and the like of a paint film are significantly improved. The preparation process is simple, the prepared emulsion has good performance, and prepared paint has good performance. Therefore, the one-component aqueous self-crosslinking acrylic polyurethane core-shell emulsion has a great application value.