The work aims to study the effect of inkjet printing droplet related parameters on their spreading characteristics, so as to lay a foundation for the study of inkjet printing quality. The Fluent software was used based on the VOF (volume of fluid) method to establish and spread a simulation model of droplet impact on the surface of a smooth substrate, and the PISO (Pressure-Implicit with Splitting of Operators) algorithm was used to couple the speed and pressure. The effect of droplet related parameters on its impact spreading was analyzed. The results showed that when the droplet flying speed was 6 m/s, the contact angle was 40°, the droplet fluid viscosity was 0.005 Pa.s, and the droplet diameter was 0.08 mm, the droplet had the highest spreading coefficient, the best spreading degree, and the best spreading characteristics when impacting the smooth substrate surface. The spread coefficient decreases with the increase of droplet diameter, fluid viscosity and contact angle, and increases with the increase of flight speed.