The invention discloses an n-type acridine/carbon nanotube composite thermoelectric material and a preparation method thereof. The n-acridine/carbon nanotube thermoelectric material is prepared by combining 3,6-diaminoacridine derivatives with single-walled carbon nanotubes. Compared with traditional inorganic thermoelectric materials, the novel n-type acridine/carbon nanotube composite thermoelectric material not only has high Seebeck coefficient, conductivity and power factor, but also has good flexibility and certain mechanical properties, so that the novel n-type acridine/carbon nanotube composite thermoelectric material is expected to be applied to flexible wearable thermoelectric equipment. As compared with the traditional inorganic thermoelectric material, the material has the advantages that the preparation method of the invention is simple and easy to realize, the cost is low and the material is easy to process and form.