Rational design of polyelectrolytes that simultaneously meets the requirements for anion exchange membrane (AEM) and ionomer (AEI), especially the opposite gas permeation demands for anion exchange membrane water electrolysis (AEMWE) with similar chemical structure is challenging. To overcome the formation of insoluble gel at high branching ratio (BR), herein, a series of anion exchange polyelectrolytes of intrinsic microporosity with wide-ranged fractional free volume and good solubility at high BR are fabricated through a stepwise nonstoichiometric superacid-catalyzed polycondensation reaction. By precisely controlling the BR and free volume, a stable and porosity-adjustable structure is generated, which not only addresses the conductivity-toughness trade-off of AEM but also possesses high OH