<p>Aluminum oxide ceramic films (AOCFs) have extensive applications in high-temperature protection, electronic device insulation, and optical coatings. However, conventional ceramic film fabrication processes typically rely on high-temperature and complex conditions. These limitations on the substrate equipment and process conditions hinder large-area, low-cost, and rapid production, which is necessary for high-performance industrial applications. Liquid metals (LMs) are emerging functional materials that exhibit both metallic and fluidic properties. Their unique characteristics, including fluidity, self-oxidation, solubility, and printability, offer a novel approach to fabricating new materials. This study proposes the direct printing of AOCFs at ambient temperature using LMs. Firstly, 3 wt% Al powder was uniformly dispersed into the eGa_0.85Sn_0.15 to form an eGaSn-Al soft composite material. Upon exposure to deionized water, the material enables the electrochemical activation of aluminum, which reacts with atmospheric oxygen to form a uniform and dense AOCF on substrates of arbitrary shape and material, with dimensional deviation of less than 0.01 mm. Leveraging the excellent printability of liquid metals, this method enables patterned fabrication of ceramic structures under ambient conditions, overcoming the reliance of conventional processes on substrate heat resistance and large-scale vacuum equipment. Furthermore, the process demonstrates high sustainability, with over 95% liquid metal recovery, significantly reducing manufacturing costs and environmental impact. The LMs-based synthesis strategy developed here offers a green, rapid, and sustainable pathway for the fabrication of OCFs, thus opening up a new research avenue.</p>