Zn‐ion batteries (ZIBs) have garnered growing interest in large‐scale energy storage devices for the high safety, high theoretical capacity and low electrochemical potential. Nevertheless, their widespread applications are significantly impeded by dendrite formation, hydrogen evolution and corrosion reactions of Zn anodes. Herein, a bi‐functional polyacrylic acid (PAA) modified‐Zn anode (Zn‐PAA) is designed to concurrently inhibit Zn dendrite formation and alleviate side reactions. The bi‐functional PAA coating not only selectively acid‐etches the active Zn crystal facets to guide the planar deposition along the highly‐exposed Zn(002) crystal facet, but also facilitate uniform Zn deposition through coordination between the polymer functional groups and Zn2+. Meanwhile, the electrically‐insulated PAA protective layer effectively separates Zn anodes from the electrolyte and modulates the solvation structure of Zn2+.6H2O, significantly suppressing side reactions. Consequently, the assembled Zn‐PAA//Zn‐PAA symmetrical cell delivers an outstanding cycling stability of 1600 h at 1 mA cm−2 and 1 mAh cm−2. The assembled KVO//Zn‐PAA full cell shows exceptional cycling stability over 1500 cycles at 2.0 A g−1 with a high Coulombic efficiency approaching 100%. The facile bi‐functional surface modification strategy, which enables to finely tune the crystal facet texture and ion distribution manner, opens up a groundbreaking path towards safe and durable ZIBs.