Abstract: In order to establish a drying method for Haematococcus pluvialis with great application value, the spray drying conditions for harvested H. pluvialis in the pilot-scale (evaporation capacity of 25 kg·h⁻¹) and production scale (evaporation capacity of 250 kg·h⁻¹) were optimized and amplified. The results showed that inlet temperatures ranging from 130 to 180 ℃ had no significant effect on the physicochemical indexes in the pilot-scale. When the outlet air temperature in the pilot scale increased from 50 to 75 ℃, the moisture content increased, but no obvious variations in astaxanthin content and protein content were found. The total solid mass fraction could significantly affect the energy consumption, production efficiency and yield of spray drying, and the optimal total solid mass fraction for spray drying was 14.60%. The key factors affecting the quality of algae powder were the drying time for droplets and the peclet number for heat, both of which could be adjusted by the outlet temperature. The scale-up of the spray drying process of H. pluvialis powder was finally achieved by optimizing the outlet air temperature, with the production efficiency of 37.04 kg·h⁻¹ and the yield of 98.57%. The process had commercial application value, and realized the scale production of H. pluvialis powder.