The invention relates to a detecting device for nodal displacement after displacement of head of hummers, belonging to technology field of biological mechanics test. The calibrating disk is fixed in disk foundation, the loading rocking bar is installed on calibrating disk, two retaining pieces are fixed in the center of loading rocking bar, one end of the head of humerus detecting is installed in the locating tank in middle of two retaining pieces, and the other end is equipped with scapula, which is installed in gripper mechanism for scapula, two blocks imitating muscle tensile force system are respectively fixed on block foundation and gripper mechanism, one end of rope is fixed on scapula and the other end is suspended with heavy objects. The binocular computer vision system aligning the symbolic object for nodal point of head of humerus. The data collecting system is collected with binocular computer vision system. The detection device in this invention not only meets the demand of two experiments of inside and outside rotating and anteflexion, but also solves problem of additional loading caused by inaccurate alignment, which reduces experiment fee greatly.