The work aims to select the best spraying condition in the process of forming vegetable compound paper by laminating. PIV (particle image velocimetry) technology was applied to measure the velocity field distribution of soybean protein solution's sprayed atomized particles under different spraying parameters. The effects of spraying parameters on the velocity field distribution of soybean protein solution's sprayed atomized particles were processed and analyzed with the data analysis software Tecplot. Finally, the change law of velocity on the central axis of spray velocity field and some section was obtained. When it reached certain spraying pressure, the sprayed particle velocity increased with the increase in the spraying hydraulic pressure, but it was not quite obvious. When the spraying hydraulic pressure remained unchanged, the sprayed particle velocity decreased and then increased with the increase in the spraying pressure. In the axial direction of the spray field nozzle, the atomized particle velocity increased rapidly after it was ejected from the nozzle, and then gradually presented a tendency of fluctuation with the increasingly farther distance from the nozzle, and finally, it tended to be stable. In the cross section 300 mm away from the nozzle, the particle velocity was the largest in the axis, and it decreased outwards gradually along the radial direction. The particle velocity was symmetrical to the center generally. The study on the sprayed particle velocity field of soybean protein solution with PIV technology is conducted and it can provide a powerful reference for the test data of forming vegetable compound paper by laminating in the later periods.