Abstract: A mechanism is established for the dual-foot biped robot with the vacuum sucker composed of three flexible hinge suction cups, and the curvature range in which the robot can move is analyzed. Based on the static force analysis, the force and torque equilibrium equations are derived under different rotation angles. The stability constraint equations are built for the suction cup radius and the gravity center position of the robot under the anti-sliding and anti-turning-over conditions. Through MATLAB optimization simulation, the minimum adsorption force for guaranteeing stability is solved, and the relationships between the climbing safety factor and the foot joint angle, the gravity center position are given and analyzed. The results show that the safety factor is nonlinear to the foot joint angle, its minimum value is obtained at robot horizontal pose, and the robot stability can be adjusted by the gravity center position. The physical prototype robot is developed and implemented to indicate that the proposed robot can climb and rotate on the wind turbine blade.