<p>The electrochemical reduction method was employed to address the issue of excessive nitrate pollution in groundwater by removing nitrate from water. The Cu-Bi-Pd trimetallic electrode was fabricated via the electrodeposition method. SEM, EDS, and XRD characterized the Cu-Bi-Pd electrodes of different metal ratios. The effects of Cu-Bi-Pd electrodes on NO₃⁻-N removal ratio and N₂ selectivity were studied under different metal ratios, electrodeposition current density, electrodeposition time, and solution electrodeposition temperature. The results showed that Cu, Bi, and Pd were uniformly loaded on the Ti matrix. Increased Bi content led to a more complete coating, a larger electrode surface grain size, and a higher degree of crystallization. The addition of the Bi element significantly improved the electrocatalytic nitrate reduction performance of the Cu-Bi-Pd electrode. The removal rate of nitrate has increased by approximately 1.28 times. The Cu-Bi-Pd trimetallic electrode with a mass ratio of 90:9:1 had better catalytic activity for nitrate, under the preparation conditions of the electrodeposition current density of 4 mA cm⁻², electrodeposition time of 50 min, and solution electrodeposition temperature of 28 ℃. The NO₃⁻-N removal ratio and N₂ selectivity were 97.6% and 57.7%, respectively. The Cu-Bi-Pd trimetallic electrode exhibited strong stability and corrosion resistance, especially for electrodes with a metal ratio of 90:9:1. For certain real groundwater (NO₃⁻-N concentration was 100 mg L⁻¹), the NO₃⁻-N removal ratio exceeded 70% after electrolysis for 6 h. The addition of Bi enhances the adsorption of N and O in nitrate, thereby improving the NO₃⁻-N removal ratio and N₂ selectivity. In this investigation, the Cu-Bi-Pd trimetallic electrode, exhibiting excellent electrocatalytic performance, has been successfully prepared, which provides theoretical insights for the development of electrocatalytic nitrate reduction.</p>