The invention relates to a synthesis method of superfine nanorod-baculariate SnO2 nano-materials, which belongs to the technical field of materials. According to invention, technically, by taking simple water-alcohol which is a mixed solution friendly to the environment and human bodies as a solvent, a superfine nanorod-baculariate SnO2 one-dimensional nano-material is synthesized by using a hydrothermal reaction, and in the process of reaction, any toxic, harmful and volatile organic solvents such as acids, alkalis, surfactants, molding templates, catalysts and the like are not added as auxiliary solvents, therefore, the method has the characteristics of environmental friendliness, and harmlessness to the human body; and the principle of the method is implemented by that parameters such as the volume fraction of the water-alcohol, the concentration of a precursor solution, and the like are adjusted so as to form specific thermodynamic reaction conditions, and then a SnO2 nanocrystal, according to the self growth rule of the nanocrystal, and through a synergistic action process of an Ostwald ripening mechanism and directional assembling, generates a SnO2 nanorod one-dimensional nano-structured crystal. A superfine nanorod-baculariate SnO2 nano-material prepared according to the invention has good sensitivity to isopropyl alcohol, ethanol, acetone, methanol and formaldehyde gas, and according to the method, gas sensors can be manufactured.