NOVELTY - The pipe has an arc windsurfer-shaped fin symmetrical to center of a transparent insulating pipe. A single-sealing cover is installed on a U-shaped copper pipe near a mouth of the pipe. A rubber sealing ring is arranged on the single-sealing cover. A windsurfer-shaped fin is installed on a heat collecting section of the U-shaped copper pipe. The single-sealing cover provided with the U-shaped copper pipe and a windsurfer-shaped fin is installed on the transparent insulating pipe. A reflecting film sheet is adhered on a surface of a backlight side of the transparent insulating pipe.    USE - U-shaped solar fin-type heat collecting pipe.    ADVANTAGE - The pipe eliminates excessive low-efficiency heat transmission process, directly transmits irradiation energy collected by the fin into a heat transmission medium in the U-shaped copper pipe, obviously reduces the surface temperature of the irradiation side, increases the heat transmission efficiency, improves the heat effect and obviously improves effective heat collecting area of the windsurfer-shaped fin, a heat collecting groove, a reflecting heat accumulating body and suboptical black bodies. The pipe achieves a purpose of making the radiation absorption of about 96 percent, increases the thermal effect by 40 percent, reduces the production cost, and has rational structure design, high heat effect, little heat diffusion loss, high heat transmission rate and better reliability, and is simple in process and convenient in installation.    DETAILED DESCRIPTION - The windsurfer-shaped fin is single-side windsurfer-shaped fin or double-side windsurfer-shaped fin. The transparent insulating pipe is single-layer transparent insulating pipe or double-layer transparent vacuum insulating pipe. The rubber sealing ring is circular shaped, V-shaped or tubular structured.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross sectional and partial side sectional views of a U-shaped solar fin-type heat collecting pipe.