The invention provides a forming device of rapid heating and cooling separation type continuous carbon fiber thermoplastic U-shaped part. The forming device comprises an upper driving mechanism, a lower driving mechanism, a vertical guide mechanism, an upper base, an upper mold, a lower mold and a lower base, wherein the upper base, the upper mold, the lower mold and the lower base are sequentially arranged from top to bottom; a lower heating plate is arranged at the top of the lower base, a cooling mechanism is embedded in each of the upper mold and the lower mold, the upper driving mechanismdrives the upper mold to ascend and descend along the vertical guide mechanism, the lower mold is installed on the vertical guide mechanism and can ascend and descend along the vertical guide mechanism, and the vertical guide mechanism is provided with a lowest limiting mechanism corresponding to the lower mold; and the lower driving mechanism drives the lower base to ascend and descend along thevertical guide mechanism. The invention further provides a forming process of the continuous carbon fiber thermoplastic U-shaped part. The forming device of the rapid heating and cooling separation type continuous carbon fiber thermoplastic U-shaped part and the process have the advantages of being scientific in design, high in production efficiency, low in energy consumption, good in product quality, economical and applicable.