In this work, the continuous conversion of xylose to furfural in water aqueous based on micropacked bed reactors (μPBRs) with mixed solid acid catalyst of SO42−/γ-Al2O3 and HND-580 was studied. For liquid-solid process, the best conversion and yield were 96.86% and 44.65% with the reaction time of only 1.6 min at 170 °C and 2 MPa, respectively. The reaction rate constant, apparent activation energy, and space–time yield (STY) were 1.37 min−1, 47.41 kJ·mol−1, and 5.00 × 10−3 g·mL−3·min−1, respectively. Also, the CO2 can enhance the conversion of xylose to furfural in μPBRs to achieve a high selectively and yield. Compared with the batch operation, the μPBRs can greatly increase the reaction rate and STY of 1–3 order magnitude. Micropacked bed reactor could be an alternative of the batch reactor to achieve a high efficient, green, continuous, and safe dehydration process of biomass.