Bimetallic electrocatalysts have been shown to exhibit synergistic effects, facilitating the efficient catalysis of neonicotinoid pesticides degradation. However, their application is constrained by diminished active sites arising from the aggregation of metal nanoparticles. By anchoring metallic species onto nanofibres through electrospinning and achieving the in-situ integration of metal oxides with carbon fibres via thermal treatment, we successfully constructed a carbon fiber-anchored ferromanganese bimetallic electrocatalyst (FM@N-CNF), featuring uniformly dispersed metal oxides with an average particle size of 6 nm. Electrochemical characterisation confirmed that FM@N-CNF exhibited a superior electrochemically active surface area and electron transfer capability compared with monometallic catalysts. When employed as a cathode material at -0.5 V vs. SCE, FM@N-CNF achieved complete degradation of thiamethoxam within 90 minutes and maintained degradation rates above 80% over 10 consecutive cycles. The catalyst demonstrated favorable tolerance under the conditions of pollutant concentrations ranging from 5~100 mg/L, pH values of 3~11, and the coexistence of common inorganic salts. Quenching experiments in combination with electron paramagnetic resonance (EPR) spectroscopy consistently identified singlet oxygen (¹O₂) as the predominant reactive oxygen species. Liquid chromatography-mass spectrometry analysis revealed that the degradation pathway of thiamethoxam primarily involves carboxylation and carbonylation reactions.