Tribocorrosion is an irreversible transformation of materials and often causes the premature failure of engineering components. In this work, the tribocorrosion behaviour of S31254 steel was investigated on a pin-on-disc tribometer at 50 N, 0.24 m s−1. In seawater, there existed a synergy between corrosion and wear, and this synergy was controlled by potentials through deteriorating the characteristics of the contact surfaces. Especially at +0.3 V, pitting corrosion occurred on metal surface, and the generated pits became the preferred locations of wear and tear, leading to a great synergy and accelerated materials loss rate. Combining X-ray microanalysis with the morphologies of the contact surfaces, the features of abrasive wear, adhesive wear, delamination and plastic deformation were revealed. Quantitative analysis shows that mechanical and corrosion-accelerated wear determined the total mass loss of S31254 steel during tribocorrosion at different potentials.