Currently, the direct and easy–to–operate electrochemical sensing technology has promising application in food safety. Here, a novel electrochemical sensing platform based on two-dimensional (2D) sheet TiCT MXene and three-dimensional (3D) urchin–like Co(VO)(HO) (CoVO) modified glassy carbon electrode (GCE) was designed for electrochemical detection toward nitrite. The urchin–like CoVO/TiCT was obtained by hydrothermal and electrostatic self-assembly. The electrochemical properties and nitrite reaction of CoVO/TiCT/GCE were tested and studied. Under the optimal conditions, the linear response ranges for nitrite detection are 0.5–50 μM and 50–2000 μM. Furthermore, the electrochemical sensor showed satisfied recoveries for the detection of nitrite in drink water and milk samples. The excellent response of this sensor to nitrite is attributed to unique electrochemical and catalytic properties of CoVO/TiCT, as verified by density functional theory (DFT) calculations.