The invention discloses a prepressing mechanism of connector assembling equipment. The prepressing mechanism of the connector assembling equipment comprises a bottom plate and a vertical plate, and is characterized in that the vertical plate is arranged on the bottom plate, a front end face of the vertical plate is provided with a fixed plate, a front end face of the fixed plate is provided with a vertical sliding groove, a moving plate moves along the vertical sliding groove through a sliding block, the front end of the fixed plate is provided with a cylinder, a cylinder rod of the cylinder and a clamping groove on the moving plate are clamped, the bottom of the moving plate is connected with a pressure head, two ends of the pressure head are provided with insertion columns, one side of the fixed plate is provided with a position-limiting rod, and a stopping block is extended from the moving plate and located at an upper side of the position-limiting rod of the same side. The prepressing mechanism of the connector assembling equipment solves the problem that since the prepressing mechanism does not has a relatively good locating mechanism, deviation of crimping positions from correct processing positions is caused during pressing. At the same time, since no stroke limiting mechanism is provided, the strokes of the crimpling positions are too large, thereby causing problems of damage or deformation of core wires, and the prepressing mechanism of the connector assembling equipment is provided which can enable each core wire to be inserted in a correct position, and prevent the core wires from being damaged by extrusion.