SnO₂ gas-sensing film is prepared on alumina substrate by laser micro-cladding SnO₂ paste,which is obtained by mixing SnO₂ nanoparticles with organic solvent. The effect of laser power on microstructure and gas-sensing properties of gas-sensing film are researched by X-ray diffraction (XRD) and field scanning electron microscope (FE-SEM). The results show that the grain sizes of SnO₂ film gradually increase with raising laser power,while gas sensitivity to ethanol vapor decreases steadily. The gas sensitivity to 2×10-3 ethanol vapor of gas-sensing film fabricated by laser micro-cladding reaches a maximum value of 8.6,whose performance is equivalent to traditional screen-printed gas-sensing film.