In the viewpoint of ammonia economy, electrochemical N2 reduction reaction (NRR) under mild condition is a very promising approach for sustainable development. By virtue of robust activity and low cost, transition-metal-based materials become one kind of the most attractive electrocatalysts in realizing ammonia synthesis to the industrial level. However, the investigation related to NRR electrocatalysts still mainly rely on costly substance or fabrication process, which greatly restrict their large-scale applications. In this work, a simple fabricated FeS2 electrode is adopted as NRR catalysts. The abundant surface defects due to the existence of Cr element, as well as the synergistic effect between FeS2 crystal planes provided excellent electrocatalytic performance with a high NH3 yield rate (11.5 μg h−1mg -1Fe) and Faradaic efficiency (14.6%) at -0.2 V vs. reversible hydrogen electrode (RHE) toward NRR under ambient conditions. The superior catalytic performance of such non-precious metal catalysts would strongly promote the application of NRR process industrially.