This paper studied the internal-petal androgynous peripheral attachment system (APAS),its differential electro-mechanical attenuation mechanism,and the dynamics properties of the docking mechanism.The docking mechanism virtual prototyping model was establlished by using Automatic Dynamic Analysis of Mechanical Systems (ADAMS).According to the simulation,the characteristics of the mechanism's equivalent stiffness and damping were obtained.These findings have been essential in ensuring a successful mission.