The invention relates to a method for preparing antimony doped tin dioxide thin film carrier material and the carrier material which is prepared is suitable for gene chips of an unmarked electrical measuring technique. The method comprises: using antimony doped tin dioxide to sputter target material, utilizing a magnetron sputtering method to prepare antimony doped tin dioxide thin film, then, hydroxylating, amino-silanizating, and aldehydizing the thin film to modify, and preparing the antimony doped tin dioxide thin film carrier material which is modified by aldehyde groups and used for the gene chips. The carrier material which is prepared through adopting the method of the invention is characterized in that the surface is flat and compact, the thickness is even, the concentration of active groups is high, the hydrophilic property is good, the chemical stability is high, the electrical resistivity is low, and the like, the carrier material can realize unmarked electrical measurement, recognition and analysis for the high sensitivity, the high reliability and the strong specificity of biological signals, and the material is very suitable for the carrier material of the gene chips of the unmarked electrical measuring technique. The method of the invention is also characterized in that the preparing technique is simple and easy to do, the cost is low, and industrial production is easily realized.