The invention relates to a method for disproportionating methyl chlorosilane, belonging to the field of ion liquid catalysis, and discloses a method for preparing dimethyl dichlorosilane or trimethyl chlorosilane by catalyzing the disproportionating reaction between methyl trichlorosilane and a low-boiling-point substance with N-butyl pyridine chloroaluminate ionic liquid serving as a catalyst. The method for catalyzing the disproportionating reaction between the methyl trichlorosilane and the low-boiling-point substance has the advantages of simple and convenient process, high raw material conversion ratio, high product yield, low reaction temperature, short time, easily-controlled condition, catalyst reusability realized by simple liquid separation, and the like.