Purpose <p>To address the key challenges of inefficient desorption of hydrophobic organic pollutants and limited efficiency of electrokinetic remediation in polycyclic aromatic hydrocarbons (PAHs) contaminated soils, this study investigates an enhanced electrokinetic remediation technique involving the sequential combination of surfactants and dual oxidants. The study examines its removal efficiency for the typical PAHs contaminant, phenanthrene, and its synergistic mechanism, with the goal of providing a theoretical basis for the efficient remediation of low-permeability organic-contaminated soils.</p> Methods <p>Using artificially prepared aged phenanthrene-contaminated soil as the study subject, four experimental groups were designed. We employed a sequential combination strategy of “solubilization followed by oxidation” was employed. The dynamic changes in current were monitored, electroosmotic flow, soil pH, and the migration and distribution of persulfate, combined with electron paramagnetic resonance (EPR) radical identification and high-performance liquid chromatography (HPLC) quantitative analysis, and gas chromatography–mass spectrometry (GC-MS) to analyze intermediate products, The relationship between surfactants and dual oxidants as well as their influence on the degradation pathways of PAHs.</p> Results <p>Compared with electrokinetic remediation alone, the average removal efficiency of phenanthrene using electrokinetic remediation alone was only 5.02%; which increased to 22.8% after the addition of sodium persulfate. Further introduction of Tween 80 increased the average removal efficiency to 54.44%, while the addition of hydrogen peroxide resulted in an average removal efficiency of 63.9%, with a removal efficiency reaching to 85.3% near the anode. Electron paramagnetic resonance (EPR) spectroscopy detected the simultaneous presence of sulfate radicals (SO₄·⁻) and hydroxyl radicals (·OH) in the reaction system, with the latter predominating; the addition of hydrogen peroxide significantly enhanced the radical signal intensity. The migration distance of persulfate increased after the addition of Tween 80, but the introduction of hydrogen peroxide accelerated the consumption of persulfate. Gas chromatography–mass spectrometry (GC-MS) analysis of the degradation intermediates of phenanthrene suggested a potential degradation pathway.</p> Conclusion <p>The sequential ‘solubilization-first, oxidation-second’ electrokinetic remediation strategy proposed in this study effectively promotes the desorption and migration of phenanthrene from soil and significantly improves phenanthrene removal efficiency through the synergistic action of surfactants and dual oxidants. Radical oxidation is the primary mechanism for phenanthrene degradation, with hydroxyl radicals playing a dominant role. Analysis of degradation products detected intermediates such as 9,10-phenanthrenequinone and 9-fluorenone. This study provides important theoretical support for understanding the mechanism and engineering applications of the surfactant-oxidant combined electrokinetic remediation technology.</p>