Objective: The study focused on investigating the electrochemiluminescence properties of graphene quantum dots. Methods: By doping heteroatoms into graphene quantum dots (GQDs), the surface chemical reactivities and optical characteristics of GQDs could be effectively improved. Nitrogen and sulfur co-doped graphene quantum dots (NS-GQDs) were prepared using a one-step solonthermic method. Based on its excellent luminescent properties, an “off-on” electrochemiluminescence (ECL) sensor was constructed for the simultaneous determination of Fe³⁺ and F^-. Results: Under the optimal conditions, the quenched ECL value of NS-GQDs was linearly related with the Fe³⁺ concentration in the range 0.1~460.0 μmol/L, and the detection limit was 0.028 μmol/L; Meanwhile, the restored ECL value was linearly related with the F- concentration in the range 1~5 600 μmol/L, and the detection limit was 0.62 μmol/L. Conclusion: The quenching and restoring of the ECL signal had good reversibility. The proposed method was successfully applied to the determination of Fe³⁺ and F^- in water samples, suggesting its potential and significance in food analysis in the future.