The invention relates to the technical field of valves, in particular to pneumatic-control combined valve mechanism. The pneumatic-control combined valve mechanism comprises a combined valve and a pneumatic control system controlling the combined valve. The combined valve comprises a valve body, a first valve element, a second valve element, a first valve rod connected with the first valve element and a second valve rod connected with the second valve element, wherein the first valve element and the second valve element are arranged in the valve body. A through medium flow channel is axially arranged in the valve body. The valve body is formed in the manner that a first main valve body and a second main valve body are connected each other. A first valve cavity is arranged in the first main valve body, and a second valve cavity is arranged in the second main valve body. The combined valve mechanism is suitable for the coal chemical industry and has the advantages of being high in automation degree, good in wear resistance, high in seal performance and long in service life.