The invention relates to the field of daily chemicals and the medicine industry, in particular to an amphiphilic amido inulin and a preparation method thereof. The amphiphilic amido inulin is shown in a formula (1), wherein R is H, CH3, CH3CH2CH2, (CH3)2CH or C6H5; and the average numeric area of n is 10-35. The preparation method comprises the following steps of: performing halogenating reaction on the primary hydroxyl of inulin; after reaction, reacting with sodium azide or lithium azide at 40-70 DEG C for 8-24 hours; purifying to obtain 6 azide-3,4-succinate-6 deoxidized inulin; and reducing the 6 azide-3,4-succinate-6 deoxidized inulin by utilizing triphenylphosphine, so as to obtain the amphiphilic amido inulin. According to the pepaation method, the amphiphilic amido inulin is obtained by virtue of an effective synthesis means, halogen is used for replacing the primary hydroxyl of inulin so as to cause that the sixth-site group of the inulin is ionized easily, acyl is used for protecting the naked hydroxy, at the othe sites, of the inulin, azido is used for performing nucleophilic substitution on the sixth-site group which is ionized easily, and the product is reduced so as to obtain the amphiphilic amido inulin with high substitution degree. The preparation method has the advantages that the synthesis step is simple, popularization is easy, and required equipment and raw materials are easily available. The formula (1) is shown in the specification.