The invention discloses an Ag-Cu alloy in-situ fibre composite material with high strength, high electrical conductivity and low Cu content and a preparation technology thereof. The Cu content of thecomposite material is equal to or less than 20% by weight percent; the in-situ fiber composite material is formed by utilizing Ag-Cu alloy eutectic structure and adopting great deformation and reasonable heat treatment technology. The preparation technology comprises the following steps: pouring Ag-Cu alloy in the protective atmosphere after vacuum smelting; carrying out hot extrusion, ageing preheat treatment, cold large strain processing, intermediate heat treatment and stabilizing heat treatment to manufacture Ag-Cu composite material with strengthened Cu fiber in the dimensions of micron,submicron or nanometer. Composite material with optimal combination of tensile strength and electrical conductivity performance can be obtained by optimizing various technological parameters in the manufacturing process. The highest performance can reach that the ultimate tensile strength UTS is equal to or greater than 1GPa, and the relative electrical conductivity is equal to or greater than 60%IACS. The Ag-Cu in-situ composite material can be used as conducting material with high strength and high electrical conductivity.