Automated fiber placement(AFP) is being widely used for producing large and complex composite structures, and ultraviolet(UV) curing has been proved as a good alternative to traditional thermal curing as a low-cost and environmentfriendly curing method. A new manufacturing method combining AFP and UV in-situ curing was presented in this paper to manufacture glass fiber reinforced composites for large scale composite structures, especially with thick curing depth.A robot-based fiber placement machine integrating UV-LED for the in-situ curing was developed and a flat panel was fabricated with this method. UV transmission characteristic of single composite layer was obtained and preliminary researches about the effects of UV exposure on laminate performance have been conducted. The results showed that laminates fabricated by the in-situ curing process shows better interlaminar properties when the degree of polymerization is about 67.7% for the first cured layer with the incident UV irradiance. Finally, some key issues concerning the process are discussed.