Robust electrochemiluminescence (ECL) of carbon nitride (CN) requires efficient electron‐hole recombination and the suppression of electrode passivation. In this work, Au nanoparticles and single atoms (AuSA+NP) loaded on CN serve as dual active sites that significantly accelerate charge transfer and activate peroxydisulfate. Meanwhile, the well‐established Schottky junctions between Au NPs and CN act as electron sinks, effectively trapping over‐injected electrons to prevent electrode passivation. As a result, the porous CN modified with AuSA+NP exhibits an enhanced and stable ECL emission, with a minimal relative standard deviation of 0.24 %. Furthermore, the designed ECL biosensor based on AuSA+NP‐CN shows a remarkable performance in detecting organophosphorus pesticides. This innovative strategy has the potential to offer new insights into strong and stable ECL emission for practical applications.