The invention discloses a pain ball bomb throwing device mounted on an unmanned aerial vehicle, which comprises a mounting plate used for being connected with the unmanned aerial vehicle. An upper plate is connected to the lower portion of the mounting plate through a quick release piece, and multiple pairs of bomb cylinders are symmetrically installed on the two sides of the upper plate; a plurality of spring columns are symmetrically arranged on the mounting plate in a penetrating mode through clearance fit, the spring columns correspond to the axes of the bomb cylinders in a one-to-one mode, the portions, located below the mounting plate, of the spring columns are sleeved with pressure springs, and the spring columns are tightly pressed on the top faces of the pain ball bombs under theaction of the pressure springs; a bottom plate is connected to the lower end between the multiple pairs of bomb cylinders, a steering engine is arranged at the position, corresponding to each bomb cylinder, of the bottom plate, and a spring bolt is installed on an output shaft of each steering engine; a supporting plate is hinged to the outer side of the lower end of each bomb cylinder, and the free end of each supporting plate is clamped on the spring bolt and used for limiting the pain ball bomb contained in the corresponding bomb cylinder. The device can continuously throw multiple pain ball bombs, can guarantee the safety of operators, and is compact in structure and high in throwing speed.