The invention discloses a nano fishbone product as well as a preparation method and application of the nano fishbone product, and belongs to the field of functional food. The preparation method of the nano fishbone product comprises the following steps of immersing cleaned fishbones in proper amount of water, stewing and softening the fishbones in a high-pressure digester, pouring out stewing liquid, adding water and rinsing, and draining off; breaking the fishbones with a meat grinder with the screen plate pore diameter of 2-10mm, drying, carrying out coarse grinding, and sieving by a 140-mesh sample separation sieve, thereby obtaining fishbone powder or fishbone paste with the particle size of less than 105 microns; and adding water into the fishbone powder or fishbone paste, regulating the water content of a dispersion liquid to 60-90%, and grinding by a high-energy ball mill at the speed of 2,000-3,000 rpm for 0.5-2 hours, wherein the size of the grinding medium is 0.5-5cm, and the filling content of the medium reaches 60%-80%. The nano fishbone product provided by the invention is emulsion which has no fishy smell, has the fishbone particle diameter of 100-300nm and has the calcium content of 30-50mg / g; the nano fishbone can be stably dispersed into the emulsion, has no gravel sense, and can be used for enhancing calcium in minced fish products and improving the texture property of the minced fish products.