The work aims to investigate electrochemical oxidation of reactive brilliant orange X-GN azo dye effluent on boron-doped diamond (BDD) electrode. BDD electrodes were deposited on niobium (Nb) substrates in hot filament chemical vapor deposition (HFCVD) method. The morphology, composition and electrochemical performance of BDD were characterized with scanning electron microscope (SEM), Raman spectroscope and electrochemical workstation. With reactive orange X-GN azo dye effluent as degradation object, effects of different process parameters such as current density (20, 50, 100, 150 mA/cm2), electrolyte concentration (0.025, 0.05, 0.1 M) and initial solution pH (3.78, 6.47, 10.92) on degradation efficiency were evaluated, respectively, and characterized and tested with ultraviolet-visible spectrophotometer. The degradation effect of X-GN was characterized by energy consumption and total organic carbon (TOC). The BDD electrode exhibited excellent electrocatalytic performance. The potential window amounted to 3.33 V, oxygen evolution potential amounted to 2.45 V, well above the oxidation potential of most organic matters. The electrode surface reaction was controlled by diffusion step. Allowing for degradation effects of reactive orange X-GN azo dye effluent, the optimal process conditions for 100 mg/L X-GN were: current density of 100 mA/cm2, electrolyte concentration of 0.05 mol/L, initial solution pH of 3.08. After 5 h treatment under these conditions, color removal rate amounts to 99%, energy consumption 65.4 kW?h/m3 and TOC removal rate 56.95%. The reactive orange X-GN azo dye effluent can be effectively degraded by BDD anode.