In this study， the optimal extraction process of hempseed protein isolated （HPI） was obtained by the response surface method. On this basis， the composition and emulsifying properties of the HPI were studied. The results showed that the optimum extraction parameters of HPI was as following： ratio of solid to liquid was 1 ∶ 20， duration time was 70 min， duration temperature was 44 ℃， duration pH was 8.3 and the protein extraction rate was（39.15±0.28）%， with a protein content of 93.54%. Hempseed protein consists mainly of globulin（edestin） and albumin. By SDS-PAGE， The protein subunits of HPI were distributed in the range of 20-50 ku. The globulin and albumin accounts for 76.41% and 23.59% of HPI. Hempseed globulin was composed of acidic subunits and basic subunits with molecular weights of 37 ku and 21 ku， respectively. The solubility and emulsification of HPI were influenced by pH， heated-temperature and duration time. The emulsifying activity tended to decrease and then increase range from pH 2-10. But with the increase of temperature and the extension of heating time， emulsifying activity tended to increase and then decrease. The emulsification was 305.53 m2/g and the emulsification stability reached 92.04% at pH 10， 55 ℃ and heated for 60 min. The emulsion of HPI was examined by micrograph which had small particle size and uniform distribution contributing to better emulsifying stability. This study provides theoretical support for the emulsification application of HPI.