The utility model discloses a flexible radio frequency cable with a low loss and a highly stable phase, which comprises an inner conductor, an insulating layer, an outer conductor and a sheath layer which are sequentially and coaxially arranged from inside to outside, wherein the insulating layer is a porous polytetrafluoroethylene film with high degree of foamability and is wound on the surface of the inner conductor, and the outer conductor comprises a silver-plated copper belt layer, a silver-plated copper flat wire braid and a silver-plated single copper wire braid; the silver-plated copper belt layer is wound outside the insulating layer, and the silver-plated copper flat wire braid is wrapped on the outer surface of the silver-plated copper belt layer; and the silver-plated single copper wire braid is wrapped at the outer side of the silver-plated copper flat wire braid. The cable has the characteristics of reduced transmission attenuation, good bending flexibility and shielding performance, and stable phase, and can be used for the high-frequency telecommunication transmission process with highly stable phase requirements.