The invention provides a semicoke-based activated carbon adsorption material as well as a preparation method and application thereof. Reaction raw materials of the semicoke-based activated carbon adsorption material comprise semicoke powder, a potassium hydroxide solution and carbon dioxide gas, and the carbon dioxide gas is used as an activating agent. The preparation method of the semicoke-basedactivated carbon adsorption material comprises the following steps: step 1, providing the semicoke powder; 2, adding the semicoke powder into the potassium hydroxide solution, impregnating at normaltemperature to obtain a sample, drying the sample, and carrying out sealed storage to obtain impregnated semicoke; and 3, heating the impregnated semicoke, activating the semicoke by using the carbondioxide gas as the activator, drying the activated semicoke-based activated carbon adsorption material in vacuum, and carrying out sealed storage. When the semicoke-based activated carbon adsorption material is applied to organic sulfur waste gas such as methyl mercaptan and carbonyl sulfide, the removal efficiency of organic sulfur can be effectively improved.