Due to the high affinity with water molecules, amide compounds are easily contaminated by moisture; therefore, the water interference effect cannot be totally excluded from the amide‐involved reactions. Thus, the perfect solution is to use the interference effect but not shield it in a real application. In this work, we introduced different contents of sodium acrylate (AAS) to scavenge water from the monomers of N‐isopropylacrylamide (NIPAm) when copolymerized with TPA‐Vinyl‐4CN. Herein, water molecules play a role as nucleophilic reagents to attack highly active functional groups as –C=C–CN from TPA‐Vinyl‐4CN, leading to a blue emissive TPA‐Vinyl‐2CHO. From this study, we made a deep awareness of the interactions between three reaction partners of AAS and NIPAm as well as TPA‐Vinyl‐4CN. Our results clearly demonstrated the fact that water can be perfectly used and controlled by the water absorbent of AAS, developing a new approach to synthesizing multiple emission‐coloured polymers by using only one luminogen of TPA‐Vinyl‐4CN.