In this paper, Ni@Co3O4-s-rGO was synthesized and constructed as a non-enzymatic sensor to detect hydrogen peroxide(H2O2). The prepared sample was characterized using SEM–EDX, UV–vis, XRD, and Raman spectroscopy. In 0.1 Mphosphate-buffered saline (PBS), the fabricated Ni@Co3O4-s-rGO amperometric sensor demonstrated a high sensitivity of 160.3 μA·mM⁻1 towards H2O2 within the linear detection range of 1 to 2000 μM. The detection limit was also determinedas 3.6 μM. Furthermore, the Ni@Co3O4-s-rGO catalyst demonstrated high selectivity towards H2O2,even in the presenceof common interferents. The enhanced electrochemical sensing ability of the catalyst is attributed to the synergy of three factors: the relatively large electrode active area, the high electrical conductivity, and the electron mobility in the presenceof ultra-nanosized Ni particles.