Abstract: IN718 nickel-based superalloy powder was spreaded at different scraper moving speeds (28.23, 63.55, 91.11, 125.25 mm·s^-1), and the powder layer thickness was 0.3, 0.5, 0.7, 0.9 mm, respectively. The powder at different positions with the same volume of the powder layer was collected by a self-made device for testing powder uniformity and weighted. The influence of the scraper moving speed and the powder layer thickness on the powder spreading uniformity was studied by calculating mass standard deviation. The results show that the mass standard deviation of the powder layer increased with the increase of the scraper moving speed or the powder layer thickness, indicating the powder spreading uniformity became worse; the scraper moving speed had a greater effect on the powder spreading uniformity. The optimal process parameter combination to obtain the best powder spreading uniformity was listed as follows:scraper moving speed of 28.23 mm·s^-1 and powder layer thickness of 0.3 mm.