The invention discloses an emission reduction system and method for gradient and cyclic utilization of waste gas of the carbon industry. By a plurality of gas delivering control units which are additionally arranged in the emission reduction system for gradient and cyclic utilization of the waste gas of the carbon industry, parameters of a plurality of adjusting valves and booster fans are adjusted reasonably, the waste gas is automatically and accurately distributed into different carbon production processes and then is utilized in a gradient manner, self-circulating utilization of the waste gas in the same production process is implemented, therefore, the waste gas used as a combustion-supporting gas is reutilized, and the effect of reducing the amount of the waste gas and emission of pollutants is achieved. For solving the problem that waste gas pollution in the carbon industry is severe, the emission reduction system and method for gradient and cyclic utilization of the waste gas of the carbon industry are provided. The emission reduction system and method for gradient and cyclic utilization of the waste gas of the carbon industry play an important role in reduction of the total amount of discharged pollutants in the waste gas and economic, reasonable and efficient utilization of latent heat of the waste gas and ingredients of the combustion-supporting gas.