Poly(amide-co-imide)-poly(trimellitic anhydride chloride-co-4,4′-methylenedianiline) (PAI-PTM) blends were prepared for fabricating nonwoven composite membranes by electrospinning method. The characteristics of the membranes were investigated by scanning electron microscopy (SEM), porometer, and universal tensile machine (UTM). Sulfonated poly(arylene ether sulfone) (SPAES) copolymer was synthesized with 50 degrees of sulfonation as a hydrocarbon-based ionomer for proton exchange membrane fuel cells (PEMFCs). The novel composite membrane was fabricated by impregnating SPAES copolymer into the PAI-PTM nonwoven membrane. The PAI-PTM nonwoven membrane exhibited high porosity and adequate mechanical properties, which could improve the dimensional stability (26 vol% decrease) from the swelling of SPAES copolymer in water. For the single cell test, the composite membrane showed comparable performance (1.07 A/cm2 at 0.6 V) to that of Nafion 212 (1.02 A/cm2 at 0.6 V) and outstanding durability in the open circuit voltage (OCV) holding test.