The invention provides a chemical method for gathering, fixing and purifying carbon dioxide, sulfur dioxide, sulfur trioxide and nitric oxide. According to the chemical method, the organic metal compound and solvent are used as the gathering and chemical fixing agents, wherein the organic metal coordinate is sulfur-containing organic bismuth and organic stibium coordinate; the solvent is organic solvent; by using the method, the gas at room temperature can be gathered and chemically fixed and form the corresponding metal salt; and the selective gradient analysis can be realized at different temperatures, so as to further realize gather and purify single gas. The capabilities of gathering and fixing agents are strong; the analysis speed is high; the regeneration energy consumption is low; the gathering and fixing agents are cheap and can be easily obtained, are simply prepared, have high stability and can be reused for several times. The method provided by the invention can be widely used for gathering and chemically fixing the room-temperature gas in flue gas, synthesis ammonia, natural gas, kiln gas, and the like, and can be used for gathering and purifying single gas.