The invention discloses a heat-transferring improved U-shaped solar heat-collecting pipe. The solar heat-collecting pipe is characterized in that an inlet flange is connected with a connecting pipe of a sleeving outer pipe, a corrugated connecting pipe, and a sleeving outer pipe in sequence; one end of a sleeving inner pipe is connected with one end of the inlet flange and one end of the sleeving outer pipe connecting pipe in a welded manner; the other end of the sleeving inner pipe is communicated with the sleeving outer pipe; a pipe wall opening of the connecting pipe of the sleeving outer pipe is connected with one end of a steam-outlet pipe, and the other end of the steam-outlet pipe is connected with a steam flange; a vacuum glass pipe is sleeved on the outside of the sleeving outer pipe and is connected with the corrugated connecting pipe in a welded manner, and a support piece is arranged between the other end of the sleeving outer pipe and a closed end of the vacuum glass pipe; and a thermal resistance inner embeded pipe is connected with the sleeving inner pipe in an interference fit manner so as to form a thermal resistance region, and the vacuum glass pipe is provided with a vacuum bleeding point. The thermal resistance inner embeded pipe is arranged on the inlet of the sleeving inner pipe, the heat-transferring thermal resistance of the liquid of the sleeving inner pipe and the gas of the sleeving outer pipe at a steam outlet is increased, thereby achieving the purposes of improving heat transfer, and ensuring and improving the quality of heat-collecting pipe outlet steam.