High-performance water-based inkjet inks are critical for advancing inkjet printing technology. The performance of water-based inkjet inks depends largely on the dispersion stability of organic pigments. This imposes higher demands on the performance of polymeric dispersants. However, the relatively weak interaction between polymeric dispersants and organic pigments limits their performance in water-based inkjet inks. Consequently, it is crucial to seek dispersants that exhibit stronger interactions with pigments, alongside high performance, and universality. In this work, five types of polymeric nanoparticles (PNPs) with anion-π groups were synthesized via a simple emulsion polymerization method. Compared to traditional polymeric dispersants, anion-π type PNPs exhibited significant advantages including low viscosity, solvent resistance, and high temperature resistance. Stronger interactions, including salt-bridge hydrogen bondings (H-bonds) and π-π interactions, between these PNPs and different types of organic pigments were demonstrated by FTIR, UV-Vis, and XPS spectral tests. In particular, PNPs-5, bearing -PhSO