The invention provides a brazed flat pipe composite aluminum strip for high-frequency welding. The brazed flat pipe composite aluminum strip comprises a middle layer, a brazing layer and a water contact layer, wherein the brazing layer and the water contact layer are respectively composited on an upper surface and a lower surface of the middle layer, the brazing layer, the middle layer and the water contact layer are prepared in a cast rolling and cold rolling production mode, and three layers of metal are tightly combined together through cold rolling compositing. The invention further discloses a manufacturing method of the brazed flat pipe composite aluminum strip for high-frequency welding. The technological process comprises the steps of smelting, cast rolling, rough rolling, homogenizing annealing, cold rolling compositing, diffusion annealing, rough rolling trimming, finish rolling, surface cleaning, finished product pre-annealing, finish rolling, surface cleaning and plate shape straightening, slitting inspection and packaging and the like. Compared with materials produced through a traditional hot rolling method, the strength before and after brazing, the welding spot quality, the pressure bearing performance after welding, the corrosion resistance and other indexes are equivalent, but the technological process is short, energy consumption is low, the production efficiency is high, the compositing rate of plate and strip materials in the width direction is uniform, the yield is high, the investment fund is small, and the risk is low.