The invention relates to a manufacturing process of a leakage liquid detection sensor of a circuit formed by utilizing ion sputtering coating. A heat-resistant and corrosion-resistant material is adopted to be taken as a substrate film, an insulating substance coating is formed on the upper surface of the substrate film by utilizing ion sputtering coating process, and two double-conduction lines are fabricated on the insulating coating through adoption of an ion sputtering coating manner; the upper surface of insulating coating is provided with a bonding layer and a protective film layer which are attached to each other; if a uniform conductive film is formed on a surface of the whole body of the substrate film or the insulating coating, film coating is performed after further coverage of a shielding adhesive tape, the shielding adhesive tape is removed after the ion sputtering coating process, and then a conduction line is formed; and a liquid leakage detection device is fabricated. The manufacturing process is advantageous in that various liquids or moisture can be prevented from resulting in corrosion occurring in the conduction line, leakage of a conductive liquid can be accurately detected, and occurrence of false alarms is minimized; reliability of the liquid leakage detection device is improved; and improvement of a bonding force between the film layers is facilitated, the stripping possibility of the upper-layer protective film layer is reduced, and the reject ratio of products is reduced.