To improve the bioavailability of phytosterols in the body and promote the wide application of phytosterols in medicine, based on the preparation of phytosterol liquid self-microemulsions, the solid self-microemulsion is further prepared by spray drying to improve its transportation and long-term storage stability. First, the type and dosage of the optimal carrier material were selected by analyzing the adsorption capacity, desorption rate, and drug load capacity. Then, with the powder collection rate as an inspection indicator, based on a single factor, the experiment carried out response surface optimization, determined the optimal process parameters of spray drying, and carried out in vitro evaluation. The results showed that the optimal carrier was colloidal SiO2, the ratio of carrier to self-microemulsion was 1:1, the inlet air temperature of spray drying was 120℃, the feeding speed was 10 mL/min, and the inlet air flow was 540 L/h. At this time, the obtained powder collection rate was the largest, the value obtained by the fitting was 49.36%, which wa basically consistent with the theoretical prediction value.There was no significant difference between the predicted value and the actual value, indicating a good fit. The prepared S-SMEDDS was the white powder with an average drug loading of 1.00%. It can be re-dispersed in water to form a light blue clear and transparent emulsion. The re-dispersed particle size was 27.20±1.15 nm and the polydispersity coefficient was 0.137±0.010. According to DSC and SEM, the drug was adsorbed in the pore size of colloidal silica in an amorphous state. Under different pH conditions, the release degree was different, but compared with the bulk drug, the release effect had been greatly improved. It showed that the self-emulsifying drug delivery system can indeed increase the solubility of the drug in water and the permeability in the intestinal tract. In addition, the solid self-microemulsion obtained by spray drying and solidification was uniform in content, easy to store and transport and the application should be considered.