The work aims to study rule of effects of critical deposition velocity of cold spray TC4 coating and particle temperature on critical deposition velocity, and also rule of effects of gas pressure on properties of deposition coating. Theoretically, Johnson-Cook model and 3D164 model in LS-DYNA software were used to study morphology characteristics of particles colliding with the substrate at different temperature and velocity, and then determine threshold deposition velocity. Experimentally, N2 as cold spray driving gas was adopted to prepare TC4 coatings on TC4 substrate. Then, SEM, Image J image analysis software, sclerometer and other methods were used to measure porosity and hardness of the coatings. Threshold deposition velocity of D=10 μm TC4 powder was 730, 465, 392 and 361 m/s at 25, 400, 500, 600 ℃, respectively, indicating that threshold deposition velocity decreased and particles could be deposited easily into coatings as powder temperature increased. TC4 coatings deposited on TC4 baseplate by adopting cold spraying technique exhibited stronger adhesion to TC4 substrate, thickness was nearly 1000 μm and porosity was nearly 6.46% provided with N2 temperature of 600 ℃ and gas pressure of 3 MPa. Threshold deposition velocity decreases as gas temperature increases; both thickness and density of the coatings prepared increase as gas pressure increases.