In this paper, we built the Cu 2 O@Ag nanocomposites-catalyzed 3,3′,5,5′-tetramethylbenzidine (TMB)-H 2 O 2 system for sensitive, rapid, and low-cost colorimetric sensing of uric acid (UA). Firstly, Ag nanotriangles were synthesized by dynamic method, and then Cu 2 O was encapsulated on the nanoflakes to synthesize Cu 2 O@Ag nanocomposites. Characterization of the structure and morphology of nanocomposites material were characterized by transmission electron microscopy, X-ray energy-dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Cu 2 O@Ag nanocomposites could catalyze the oxidation of TMB by H 2 O 2 (which is produced by enzymatic oxidation of UA), and the color changes from colorless to blue can be observed directly with the naked eyes or can be detected by UV-Vis spectrophotometer. The colorimetric sensor provided a linear absorbance response in the 0.5-100 μM UA concentration range with a 0.4 μM detection limit (S/N = 3). The recovery of UA in human serum by the proposed sensor is over 95.7%. Thus, these results imply that the UA sensor provides an effective tool in fast clinical analysis of gout without the need for expensive and advanced equipment.