Abstract: Structural lock is an electromechanical equipment that connects rigidly two space shuttles together. In this paper, the eccentric wheel plus cam mechanism scheme is selected. Based on analyzing their advantages and disadvantages, it is pointed out that this structure is simple and self-locking is reliable. Then the parameter of turning and pulling process are optimized. The optimization of structural lock during the pulling process is discusses in view of minimum torsion, minimum power and minimum time. It has been proved that the scheme optimized consumes least energy.