Abstract: Poly(aryl ether sulfone) with chloromethylation rate of 150% (CMPSF150) was synthesized, and then CMPSF150 was reacted with p-hydroxybenzyl alcohol to synthesize side-chain poly(aryl ether sulfone) (PSF-HBA150). Side chain chloromethylated poly(aryl ether sulfone) (PSF-CM150) was synthesized by reaction of PSF-HBA150 with thionyl chloride. PSF-CM150 was quaternized with piperidine and alkalized to prepare side-chain piperidine-functionalized poly (aryl ether sulfone) anion exchange membrane (QPSF-Pip150). Finally, crosslinked anion exchange membrane with different crosslink degree (cQPSF-Pipx-TAPy, x was the mole percentage of functional cation, y was the mole percentage of 2,4,6-tris(dimethylaminomethyl) phenol (TAP)) were prepared by controlling the ratio of the crosslinking agent TAP to piperidine. The polymer structure was characterized by ¹H-NMR. cQPSF-Pipx-TAPy were insoluble in any solvent, the initial decomposition temperature and tensile strength of cQPSF-Pipx-TAPy increased up to 18 °C and 14.7 MPa higher than QPSF-Pip150, respectively. QPSF-Pip150 was completely damaged after soaking in distilled water at 80 ℃ for 48 h, but cQPSF-Pipx-TAPy were intact. The water absorption rates of cQPSF-Pip130-TAP20 and cQPSF-Pip120-TAP30 were 87.4% and 72.5%, the swelling rates of cQPSF-Pip130-TAP20 and cQPSF-Pip120-TAP30 were only 19.7% and 16.4%, respectively. The ionic conductivity of cQPSF-Pip130-TAP20 was up to 131.5 mS/cm at 80 ℃, while the swelling rate is only 19.7%. Ion exchange capacity and ionic conductivity of cQPSF-Pip130-TAP20 and cQPSF-Pip120-TAP30 still remain 81.7%—91.1% and 73.1%—85.9% after soaking in 1 mol/L NaOH at 60 °C for 20 d, respectively. The mechanical properties, thermal stability, dimensional stability and alkaline stability of anion exchange membranes were effectively improved by crosslinking.