The invention provides a light-weight alkane isomerization method using ion-like liquid as a catalyst. The light-weight alkane isomerization method comprises the following steps that ingredients containing light-weight alkane are in contact with ion-like liquid so that the light-weight alkane takes an isomerization reaction, wherein the ion-like liquid is prepared from an amide compound and more than one kind of metal compound through reaction. The method has the advantages that the ion-like liquid is used as the catalyst; the synthesis raw materials can be easily obtained; the synthesis method is simple; the price is low; in addition, the ion-like liquid has high catalysis activity, high stability and high selectivity; the conversion rate of the light-weight alkane isomerization raw materials catalyzed by the ion-like liquid and the isomerous alkane content in the reaction product are greatly improved.