Precisely onsite monitoring of hypochlorite (ClO−) is of great significance to guide its rational use, reducing/avoiding its potential threat toward food safety and human health. Considering ClO− could quench fluorescence of curcumin (CCM) by oxidizing the o‐methoxyphenol of CCM into benzoquinone, a portable ratiometric fluorescence sensor integrated with smartphone was designed for realizing the visual point‐of‐care testing (POCT) of ClO−. The amphiphilic phospholipid polymer was used as carrier to wrap curcumin, forming a novel liposome‐encapsulated CCM, which provided a scaffold to bind with [Ru(bpy)3]2+ through electrostatic interaction, thus assembling [Ru(bpy)3]2+‐functionalized liposome‐encapsulated CCM ([Ru(bpy)3]2+@CCM‐NPs). Further integrated with smartphone, visual imaging of [Ru(bpy)3]2+@CCM‐NPs could be achieved and the accurate onsite detection of ClO− could be realized with a detection limit of 66.31 nM and a linear range of 0.2210 to 80.0 μM. In addition, the sensor could monitor ClO− in real samples with an onsite detection time of ∼154.0 s. [ABSTRACT FROM AUTHOR]