Pervaporative ethanol dehydration is a promising approach to concentrate ethanol from biofuel stocks. In this study, we have fabricated high performance dual-layer cellulose triacetate (CTA)/Ultem hollow fiber membranes incorporated with a small amount of superhydrophilic carbon quantum dots (CQDs) via the immiscibility induced phase separation (I2PS) method. The flow rates of the inner- and outer-layer dopes were firstly optimized. Subsequently, various small amounts of CQDs were added into the inner- and outer-layer dope solutions to explore their impacts on membrane structure and separation performance. It was found that the incorporation of a reasonably small amount of CQDs, whether to the inner or outer layer of I2PS membranes, could significantly enhance the mechanical properties and pervaporation performance by altering their structures. The most effective membrane containing 0.2 wt% CQD in the outer layer (0.2CQD_OL) demonstrated exceptional pervaporation performance. Using an 85 wt% ethanol feed solution, this membrane achieved a total flux of 4306 ± 130 g m−2h−1 (equivalent to a water permeance of 33.28 mol m−2h−1 kPa−1) and a water content of approximately 95 wt% (equivalent to a mole-based selectivity of 153) in the permeate over a 172 hr long-term test. A comparison with literature underscores the superior performance of this newly developed I2PS membrane, particularly in terms of water permeance. In summary, the CQD-embedded CTA/Ultem HF membranes demonstrate substantial potential for industrial applications in the pervaporative ethanol dehydration.