Soil steam disinfection technology has significant advantages in preventing and controlling soil borne diseases, and is one of the important means to solve the problem of soil continuous cropping obstacles. The heat transfer characteristics of steam in soil are closely related to the specific physical parameters of the soil. The main physical parameters affecting the heat and mass transfer characteristics of Yunnan unique red soil were determined by drying method, pycnometer method, thermal probe method and Metastability plate method. The soil bulk density was 0.736 g/cm³, the soil moisture content was 26.2%, the soil particle density was 2.398 g/cm³, the soil porosity was 69.3%, and the soil thermal conductivity was 0.296 2 W/(m·℃), the specific heat capacity of soil mass was 57.840 3 J/(kg·℃). The research results provide preliminary experimental data support for subsequent soil steam disinfection experiments and the construction of heat and mass transfer simulation models.