A method for sludge dewatering using kitchen waste to synergistically enhance a coupling of an anaerobic biological acidification and a low-temperature hydrothermal of excess sludge is disclosed. The method includes the following steps: first, uniformly mixing the excess sludge from a sewage treatment plant and the kitchen waste for an anaerobic biological acidification reaction at 36.5-37.5° C. for 2-4 days; then, concentrating the acidified mixture by centrifugation at a speed of 3000-5000 rpm for 5-10 min; performing a low-temperature thermal hydrolysis treatment on a residue obtained after removing a supernatant for 15-30 min at 100-140° C.; and after the thermal hydrolysis treatment is finished, cooling and dewatering to obtain a dewatered sludge cake and a dewatered filtrate. The new method realizes high-efficiency sludge dewatering and innocuous utilization of dewatered filtrate and sludge cake without adding chemical reagents and effectively avoids generating hardly-degradable chemical oxygen demand.