The electrochemical nitrogen reduction reaction (NRR) technique has great potential for alleviating the high fossil fuel consumption and carbon emissions of the industrial Haber-Bosch method for ammonia (NH₃) synthesis. Moreover, the NRR provides great prospects for fully exploiting renewable energy since NH₃ is a promising energy carrier without carbon emissions. However, the development of the NRR technique is limited by the lack of efficient catalysts. Great efforts have been made to develop high-efficiency catalysts thus far, in which density functional theory (DFT) calculations have played an important role in assisting catalyst design. Herein, we summarize the recent catalyst design strategies to boost the NRR performance, i.e., the activity and selectivity. Additionally, representative computational studies are reviewed, accompanied by insights into further improving the catalytic behavior. Finally, we briefly discuss the challenges and opportunities in catalyst design via DFT calculations. The purpose of this review is to motivate more intelligent design strategies for high-efficiency NRR.