Abstract: The rheological properties of drug and carrier materials have a wide range of guiding significance for the formulation and process development of solid dispersions. In this study, the rheological properties of materials with different drug carrier ratios were systematically studied with suvorexant as the model drug and copovidone as the carrier material, which provided a sufficient basis for determining the formulation and process of solid dispersions. The optimal suvorexant-copovidone ratio obtained by oscillating temperature scanning was 1∶4. If the ratio is greater than 1∶ 4, the glass transformation temperature of the material will increase significantly, and the solubilization effect of the solid dispersion will show a downward trend. The results of oscillation temperature scanning and oscillation temperature sweep can show that when the extrusion temperature is greater than 150 ℃, the viscosity of the material is less than 10 000 Pa·s, and the melt can be extruded smoothly, and the best extrusion temperature of 160-180 ℃ can be obtained by combining the dissolution results. Finally, the dissolution of suvorexant tablets guided by rheological property studies in multiple media is similar to that of the commercially available tablets Belsomra. Therefore, rheological studies can screen and optimize the formulation and process of suvorexant solid dispersions at the mechanism level, which is of great significance to improve the success rate of R & D and shorten the R & D cycle of solid dispersions prepared by hot melt extrusion.