A Ni/Cu/boron-doped diamond (Ni/Cu/BDD) complex electrode for non-enzymatic glucose electrochemical detection was prepared by a simple two-step heat treatment method. Scanning electron microscopy (SEM), Raman spectroscopy and electrochemical workstation were used to characterize the surface morphology, composition and electrochemical properties of the electrode, respectively. The results showed that Ni reacted with BDD under high temperature catalytic conditions forming a porous structure, and stabilized Cu on the surface of BDD due to the superior wettability between Cu and Ni. Compared to Ni/BDD and Cu/BDD electrodes, Ni/Cu/BDD electrode exhibited enhanced catalytic activity in glucose detection, such as an extremely wide detection range (0.022–18.3mM), high sensitivity (1007.688 μAmM−1cm−2, which was 1.28 times higher than that of the Ni/BDD electrode), great selectivity and excellent long-term stability (93.3% after one month). •The Ni/Cu/BDD electrode exhibits excellent long-term stability because nickel particles are embedded into the diamond forming a porous structure, which avoids the peel-off of Ni/Cu NPs during the detection.•The Ni/Cu/BDD exhibits enhanced catalytic activity compared with Ni/BDD owing to the addition of Cu nanoparticles.•The synergistic effect of nickel nanoparticles, copper nanoparticles and BDD films is well discussed for the first time.