The surface of steel structural components exposed to extremely harsh environments is prone to rust, as a result, their normal service life is reduced, whilst the durability problem is increasingly prominent. Thus, the corrosion behavior and characteristics of surface morphology of Q690 high strength steel was assessed via alternative cyclic tests: immersion in artificial sea water, drying by indoor ventilation air and drying in atmosphere of 95% (±3%) relative humidity at 35 ℃, aiming to simulate the corrosive environment of ocean splash zone. Then, the variation of surface morphology with the progress of corrosion process and the corresponding surface coordinate parameters were collected by laser confocal microscope (LSCM). The results show that in the initial stage of corrosion, a small number of needle-like pits occurred on the surface, and the metallic luster was gradually lost. With the progress of corrosion process, the initial needle-like pits gradually developed toward large pits. At the later stage of corrosion, there exist a large number of lamellar corrosion products, and on which, exfoliations in some local areas could be observed. In addition, according to the microscopic scanning analysis, it could be seen that the cumulated corrosion products exhibited a good protective effect on the steel substrate, the corrosion process rapidly extended to the periphery and finally corrosion products completely covered the whole surface of steel specimen. When the corrosion period was 100 d, the volume loss rate and surface corrosion height were 1.38% and 840 μm, respectively.