In this paper, nanocomposites of Ag2V4O11 nanobelts with self-loaded Ag nanoparticles were prepared by irradiation treatments of Ag2V4O11 nanobelts, electrochemical analysis were performed and it is found out that the Ag/Ag2V4O11 nanocomposites significantly improved the direct electron transfer between hemoglobin (Hb) and glassy carbon electrode (GCE), leading to a very sensitive detection of H2O2 of the Hb/Ag/Ag2V4O11 modified GCE.