<p>A novel high-throughput platform enabling high-efficient preparation of droplet microarray and automatic characterization of corrosion morphologies was employed to investigate droplet corrosion on carbon steel. One hundred droplets with different compositions (NaCl and Na₂SO₄), concentrations (from 0.4 wt.% to 4 wt.%) and pH values (3, 7 and 10) were obtained within 2 h. The average height of accumulated corrosion products (<i>H</i>) in neutral NaCl droplets decreased as NaCl concentration exceeded 2.4 wt.%, while <i>H</i> value in neutral Na₂SO₄ droplets increased continuously with the increasing Na₂SO₄ concentration. Finite element modelling confirmed that the high surface coverage of corrosion products in high-concentration NaCl droplets prohibited corrosion products accumulation. The less aggressive SO₄²⁻ resulted in a low surface coverage thereby enabling continuous corrosion products formation. For the influence of pH values, the corrosion rate in acidic environment (pH=3) was the largest due to the formation of non-protective γ-FeOOH and FeCl₂, while the alkaline environment (pH=10) showed the least corrosion rate as more protective α-FeOOH was generated.</p>