The fastener installation in the wing-box faces with narrow space, and it has to be done manually at present. Since manual labor has size constraints, the efficiency is low, and there may be assembly quality instability, it urgently needs automation. Automatic fastening assembly using a robot undoubtedly is an appropriate solution. The existing industrial robots, snake robots, humanoid robots can not meet the fastening assembly requirements in the wing-box. We develop a new anthropomorphic robot with multiple links to perform the inner fastening. A prismatic pair is employed to fit the arm links entering into the wing-box. A shaft with 360 degrees rotation liked human shoulder is introduced to meet the circumferential positioning around the process hole. Arm links are used for robotic end effector reaching the local fastening site. Based on the limitation of assembly position in the wing-box, the link lengths are considered and determined. By using the geometric relation with the link lengths, the joint angle variables are presented. Then, S shape arm link is designed for the compact requirement and the dimensions are determined based on the cross-section of human arm. Finally, stable frame structure is set up through the rear door frame and the bridge beam, and the whole robot is integrated.