The assembly of large scale components are still challenging tasks due to the heavy weights of the objects, and the requirements of high precision and high efficiency. Therefore, the design of robotic assembly system for large scale components, and the studies on the corresponding methods and strategies are still very important and very urgent. In this paper, we design a new robotic assembly system for large scale components guided by two vision sensors and three 1-D laser sensors. Novel high precision localization and alignment methods are proposed to automatically localize the components and search the best three-dimensional position and orientation between the object and the installation location. Experimental results show that the system can well complete the assembly task for large scale components automatically, including automatic detection and localization, automatic grasping, automatic guidance, and automatically insertion, with high precision and high efficiency.