Based on the HVOF process, this paper aims to investigate the effect of particles impact velocity on the deposition behavior of WC-12Co particles on the substrates. The deposition behavior of a single particle on the same substrate was simulated and analyzed using SPH method in the velocity range of 400~800 m/s. It is found that the particle impact velocity has a close relationship with the particle flattening rate, the bonding area, and the bonding method. With the increase of the impact velocity of the particles, the depth of the crater continuously increases to 4.6 times of the minimum depth. The metal jet promotes the improvement of the flattening degree of the particles and the effective bonding area between the particles and the substrates. The total contact area can reach 2.7 times of the original effective contact area at the maximum. With the increase of impact velocity, the effective plastic strain, strain area, and deformation area are increased. The temperature rise at that bonding surface increases, enhancing the bonding condition of the particles and the substrates. Energy dissipation exists in the deposition process. The increase of initial energy is beneficial to the increase of the total energy of particles and substrates, and strengthens the compaction effect and further promotes the combination of particles and substrates.