[en] Highlights: • Ultrafine nanocrystals modified high-entropy alloy composites (HEACs) were fabricated. • With YPSZ addition, the HEACs exhibited the finer microstructure free of the micro-crack. • Relative stable atomic group of UNs owned short-range order was produced. • Nanoscale icosahedral quasicrystals with five-fold symmetry are obtained in HEACs. • With SiB₂ addition, lots of one-dimensional nanostructure materials were produced. Ultrafine nanocrystals (UNs) modified high-entropy alloy composites (HEACs) were fabricated by laser-melted deposition (LMD) of the yttria partially stabilized ZrO₂ (YPSZ) and the FeCoCrAlCu mixed powders on the aviation turbine blade made of the additive manufacturing (AM) TC17 titanium alloy. Such HEACs exhibited the finer microstructure free of micro-crack under an action of YPSZ, also relative stable atomic group of UNs owned the short-range order was produced attached to such HEACs matrix. Formation mechanisms of the AlCu₂Zr UNs, amorphous and the nanoscale icosahedral quasicrystals (I-phase) with five-fold symmetry in HEACs were explored extensively by mean of the high resolution transmission electron microscope (HRTEM); also, under the actions of these various phases, such laser-induction HEACs exhibited the better wear performance than that of the FeCoCrAlCu LMD high-entropy alloy. With SiB₂ addition, lots of the one-dimensional nanostructure materials (nanorods) were produced, retained UNs can be easily reunited due to a surface effect, retarding growth of nanorods in a certain extent. This research may provide the essential theoretical and experimental basis to improve the quality of the laser 3D print composites.