Abstract: Aiming at the safe operation of gas turbine, to ensure the good cooling effect of disk cavity and the reliability of disk strength, the flow heat transfer of disk cavity and thermo-solid coupling characteristics of disk are numerically studied in this paper. An analytical model of three-stage disk cavity is established, and the effects of rotational speed and flow rate on the flow heat transfer characteristics of the disk cavity are studied and compared. The stress and deformation characteristics of disk are analyzed based on the flow heat transfer results. The results show that when the rotational speed increases, the pressure loss in each chamber decreases, and heat exchange surface Nu decreases by 66.1% at most. When the flow coefficient increases, the pressure loss in each chamber increases, and Nu of some heat exchange surfaces presents an upward trend, up to about 198%. The maximum radial deformation is 2.62 mm and the maximum equivalent stress of the disk is 996.06 MPa under the comprehensive action of various loads. The research results provide technical support and reference data for ensuring the safety of gas turbine disk.