The large aircraft skin presents large deformation after clamping， and direct processing according to the theoretical program will lead to the scrapping of the parts. The actual shape of the skin surface measured on the machine is an important guarantee for the parts to be qualified. However， the traditional contact detection method is inefficient and affects the manufacturing cycle of the parts. In order to solve the above problems， a multi-source integrated on-line measurement （MSIM） for skin is proposed in this paper. In this method， firstly， the large-scale skin on-board laser scanning hardware integration is used to realize the large-scale skin on-board fast scanning. Then， based on the high-precision contact measurement data， the residual approximation model between multi-source measurement data is established， and then the high-precision skin actual surface is generated through weighted integration. Experiments show that the actual surface of large-scale skin generated by this method has obvious advantages over the related methods， and meets the needs of high-precision and efficient in-flight measurement of large aircraft skin.