The mechanical and deformation of the transmission tower foundation are related to the safety and cost of the transmission project. Large-angle corner towers often need to be constructed in the stratum of thick soil overlying bedrock in mountainous areas，therefore，the required uplift and horizontal loads are large. The proposed new cable anchored platform foundation shows good applicability for the above-mentioned conditions. In order to study the bearing capacity of this foundation，the mechanical and deformation characteristics of the foundation under combined uplift and horizontal loads were investigated via theoretical analysis，numerical simulation and in-situ ex? periments. The results show that the uplift and horizontal resistance can be guaranteed by the inclined arrangement of the cable and the applied pre-stress in cables. The deformation of the foundation can be effectively controlled when the pre-stress value of the cable is set to 90% of the design uplift load. The numerical simulation and in-situ experi? ment results show that the foundation deformation and cable axial force meet the design requirements when the ap? plied load is equal to the design load，indicating the feasibility and applicability of the foundation scheme. The de? structive experiment shows that the failure mode of the foundation is the concrete cracking caused by insufficient punching shear strength of the platform concrete. This research provides a reference for the design and calculation of the cable anchored platform foundation and its further application in the transmission tower.