The work aims to fabricate nano Fe-Al/Cr3C2 composite coatings, compare and analyze adhesion strength, microhardness and porosity, so as to provide an effective technical method for treating damageable parts by applying thermal spraying technology. Reunion-granulation was successfully applied to highly active nano Fe-Al/Cr3C2 composite spraying materials by using independently developed reunion-granulation system. Nano-Fe-Al/Cr3C2 composite coatings were made on structural materials in the method of high velocity flame spraying (HVFS). Basic properties of the nano Fe-Al/Cr3C2 composite coatings, including adhesion strength, micro-hardness and porosity were tested. Particle size of Fe-Al/Cr3C2 composite spraying materials changed from 50 nm to 114~178 nm. The nano spraying particles after reunion-granulation were round or oval, proportion of ingredients in granulated particles stayed the same, inner particles of granulated particles kept nanometer state. Elements on the surface and cross section of the nano Fe-Al/Cr3C2 composite coatings were dense and uniformly distributed. The porosity, micro-hardness and adhesion strength of nano Fe-Al/Cr3C2 composite coatings was 0.25 times, 1.39 times and 2.43 times as great as micro Fe-Al/Cr3C2 composite coatings, respectively. Reunion-granulated particles meet relevant requirements of thermal spraying materials completely. Compared with micro Fe-Al/Cr3C2 composite coatings, nano coatings have finer coating structure and superior basic properties.