The invention discloses an annular air supply vertical foam generating device. The annular air supply vertical foam generating device comprises a liquid supply connector, an air supply connector, a foaming barrel, a foaming net, a foam transporting pipeline, an atomizing nozzle and a base. The base is provided with the liquid supply connector and the air supply connector. The upper end of the base is connected with the lower end of the foaming barrel. The atomizing nozzle is arranged on the lower portion of the inner side of the foaming barrel and is connected with the liquid supply connector through a liquid supply pipeline. The foaming net is arranged on the upper portion of the inner side of the foaming barrel, and the upper end of the foaming barrel is connected with the foam transporting pipeline. The annular air supply vertical foam generating device solves the problems that in the existing coal mine underground foam dust prevention technology, the foaming capacity of a foam generator is poor, the foam outlet pressure of a traditional foam generator is low, spraying strength is small, and foam distribution is not uniform.