Abstract: In order to study the effect of the agglomerate metal particle on the coatings building-up, the agglomerate nano metal particle deposition characteristics with smoothed particle hydrodynamics(SPH) were simulated in low temperature high velocity air fuel(LTHVAF) thermal spraying process.The results show that the agglomerate particles are splashed when the agglomerate particles impact on the substrate.During the deposition process, the effective strain of agglomerate particle is larger than that of the micron particle, but the area ratio of the agglomerate particle is less.At the same time, the pervasion occurs when the metal particle impacts on the substrate, which increases with the particle velocity.