Recognition, quantification, and selective removal of target heavy metal ion with a single material are of great practical importance, while there still remains a formidable challenge of accomplishing these multiple tasks in pure aqueous media. Herein, we utilized crosslinked poly(ionic liquid) as support of organic probe to devise a new class of multifunctional material for addressing this issue while simultaneously providing some additional benefits. To illustrate this strategy, an imidazolium-type crosslinked poly(ionic liquid) anchored with rhodamine derivative, P(RhBHSA-BVD), was designed and applied for qualitative/quantitative analysis and selective removal of Cu2+. In significant contrast from previously reported organic probe/support composites that were typically hydrophobic and usually required use of organic solvent to disperse them before use, the P (RhBHSA-BVD) was highly hydrophilic and readily dispersed in pure water. Moreover, due to the positively charged nature of polymeric backbone, the P(RhBHSA-BVD) had a potential advantage of avoiding non-receptor binding. Observation with naked eye confirmed the highly selective and sensitive response of P(RhBHSA-BVD) to Cu2+, and accordingly a convenient colorimetric sensing method for detection of Cu2+ was successfully established. Furthermore, it was demonstrated that the P(RhBHSA-BVD) could selectively remove Cu2+ from multi-ions solution with high efficiency and excellent reusability.