The invention provides a four-bar linkage mechanism in a separation connector of an airborne weapon system. The four-bar linkage mechanism comprises a cover plate, linkage bar bases, rotation shafts,linkage bars, gaskets, screws, an installation support, steel balls, springs and fixation nuts and the like. The linkage bar bases, the rotation shafts and the linkage bars form linkage bar components. The four linkage bar components are mutually independent. Each linkage bar is provided with a circular arc groove. One ends of the linkage bars are fixedly arranged on the linkage bar bases throughthe rotation shafts respectively, and the other ends are fixed to the installation support. The installation support is provided with stop steps. Pre-tightening structures formed by the steel balls, the springs and the fixation nuts are mounted in the stop steps respectively. The installation support is provided with an installation hole, which can be in matched installation with different seriesof connectors, and meanwhile, plays a tail accessory function, and helps output of a connector cable. A platform at the upper end of the installation support can provide mechanical power for other stop mechanisms in follow-up separation process of the connector.