The invention belongs to the technical field of chemical engineering, and particularly relates to a method for separating components in a mixture containing methylbenzene, 2-methylthiophene and 3-methylthiophene. According to the method, 2-methylthiophene and 3-methylthiophene in the mixture containing methylbenzene, 2-methylthiophene and 3-methylthiophene with very close boiling points are converted into substances 2-chloro-5-methylthiophene and 2,5-dichloro-3-methylthiophene with boiling points greatly different from the boiling point of methylbenzene by adopting a chemical method for the first time; then the components are separated and purified by adopting a rectification method, and the 2-chloro-5-methylthiophene and the 2,5-dichloro-3-methylthiophene are treated by adopting a reduction method and the like to obtain single-component 2-methylthiophene and 3-methylthiophene, so that the methylbenzene, the 2-methylthiophene and the 3-methylthiophene are separated. The method is simple in process, high in product yield and purity, good in separation effect, low in energy consumption and free of emission of three wastes(waste gas, waste water and industrial residues), and is a green separation process.