Objective Using Dunaliella spp. powder as the raw material, to explore the effect of pH value, alkali dissolution temperature, alkali dissolution time, and solid-liquid ratio on Dunaliella spp protein extraction.Methods The optimal conditions are screened by single-factor experiments. Response surface experiments are designed by the Box-Behnken method to determine the optimal extraction process parameters for Dunaliella spp. protein with the Dunaliella spp. protein extraction rate as the indicator. Additionally, the group composition, secondary structure, amino acid composition, and functional properties of Dunaliella spp. protein are determined.Results The optimal extraction process conditions for Dunaliella spp. protein is pH 10.54, alkali dissolution temperature 51 ℃, alkali dissolution time 2.1 h, and a solid-liquid ratio of 1:206 (g/mL). Under these conditions, the extraction rate of Dunaliella spp. protein is 52.98%. At 50 ℃, Dunaliella spp. protein exhibits the highest water and oil holding capacity. At a mass fraction of 0.6%, Dunaliella spp. protein exhibits the highest foaming property (40%), foam stability (62.5%), emulsifying property (62%), and emulsifying stability (66%). Structural analysis shows that the secondary structure of Dunaliella spp. protein is mainly β-sheet (26.79%), with essential amino acids accounting for 32.94%, and hydrophobic amino acids accounting for 39.52%.Conclusion The optimized extraction process for Dunaliella spp. protein can significantly increase protein extraction rate.