Cellulose aerogel beads (CABs) have emerged as advanced biomaterials with numerous engineeringapplications, including chromatography and drug release. In this study, porous core–shell CABs were synthesizedusing a dilute ethanol solution-substitution-assisted freeze-drying. The formation mechanism ofthe CABs and the effect of ethanol concentration on the core–shell microstructures and physical propertieswere investigated. Cellulose hydrogel beads (CHBs) were formed through the exchange/neutralizationof acetic acid with tetraethylammonium hydroxide (TEAOH)/urea. The cellulose chains dissolvedin the cellulose–TEAOH/urea droplets regenerated from the edge to the inside of the droplet in an aceticacid bath. Notably, adding ethanol at a concentration of 10% before freeze-drying can result in core–shellCABs with non-obvious structural shrinkage, large particle size, uniform pores, and high porosity. Ethanolmolecules induce ice crystal growth to form more uniform ice crystals during the freezing process. Additionally, by altering the TEAOH/urea molar ratios and cellulose concentrations of cellulose solutions,well-shaped and porous CABs were prepared, demonstrating the feasibility and availability of dilute ethanolsolution-assisted freeze-drying. Consequently, the as-fabricated CABs had a dense micro-shell(1–9 lm) and loose millimetric-core with anisotropic pores (2–6 lm), exhibiting low density (0.06–0.09 g/cm3), high porosity (87.0–91.5%), and noteworthy thermal stability.