This work was aimed to analyze the law of the spray atomization in the production of the vegetable composite paper, and to study the change in the atomization field′ s speed of the soy protein spraying fluid under different coating conditions. Firstly continuous spray images were collected by high-speed cameras. Then correlation analysis of the collected image sequence was conducted to obtain the relative displacement field of the image pairs. Finally, combined with the images′parameters acquired by the high speed camera, the speed field of the soy protein spraying fluid′ s atomization was calculated. Analysis was conducted with the atomized particles in the square area 10 cm below the nozzle with a side length of 10 cm. At a constant air pressure, the average velocity of soy protein atomized particles increased with increasing hydraulic pressure. At a constant hydraulic, with the increase of air pressure, the average velocity of soy protein atomized particles first decreased and then increased, and finally tended to be stabilized. After analyzing the images of atomization field collected by high-speed camera using the digital image correlation technique, the velocity distribution characteristics of the soy protein spraying fluid atomization field was described Through processing spray images under different spraying parameters, the influence of spraying parameters on atomized particle velocity was obtained.