The invention discloses a polyhexamethylene adipamide composition thickening agent. The polyhexamethylene adipamide composition thickening agent comprises the following components in parts by weight: 20-30 parts of polyhexamethylene adipamide, 2-4 parts of tin hydroxide, 1-1.5 parts of sodium bisulfite, 10-14 parts of oxidized starch, 15-25 parts of bentonite, 2-10 parts of a cross-linking agent, and 100-150 parts of deionized water. A preparation method comprises the following steps: mixing the raw materials except polyhexamethylene adipamide and bentonite according to weight part, uniformly stirring a mixture, heating the mixture for boiling, adding bentonite and polyhexamethylene adipamide in a high temperature fusion state, and mixing the materials for standing. Compared with the traditional thickening agent, the paste making rate by the polyhexamethylene adipamide composition thickening agent is high, the color paste transitivity is good while fabric printing is carried out, coloring performance is high, the polyhexamethylene adipamide composition thickening agent has good plasticity and adhesion strength, has little influence on fabric handfeeling and color fastness, and has good electrolyte-resistant performance, and the preparation method has the advantages of simpleness, environmental protection and high efficiency.