Thermomechanical treatments including hot extrusion, heat treatment and cold drawing were used to prepare Ag-15Cu in situ filamentary composites. The obtained composites can achieve a strength of 996 MPa and keep a conductivity of 62%IACS. Homogenization treatment and low temperature aging can effectively improve the strengthening potential of the material, while low temperature heat treatment of several times during drawing can greatly improve the conductivity and there is no loss of strength even at high strain. The influencing mechanism of heat treatments on the microstructure and properties were discussed