The work aims to study the effects of different water content in soil on galvanic corrosion behavior of Q235 steel-red copper galvanic corrosion behavior in typical acid red soil environment in Jiangxi province. Q235 steel-red copper coupling was coupled and placed in red soil of different humidity. Galvanic current and potential were measured with ZRA-2 galvanometer. The sample was taken out from soil for weighing to obtain corrosion kinetic curve at selected time intervals. Microstructure, composition and phase of the corrosion products were analyzed with X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy dispersive spectroscope (EDS), respectively. Main corrosion products were identified as Fe3O4, Fe2O3 and FeOOH. With the increase of water content in soil, corrosion products spallation became worse and corrosion weight loss was more significant. As Q235 steel and red copper were coupled, galvanic corrosion effect led to acceleration of carbon steel corrosion. The galvanic corrosion effect was 5.70, 4.30 and 4.08, respectively when water content in soil was 10%, 20% and 30%, respectively. At the initial stage of corrosion, the galvanic current decreased dramatically since corrosion products took shape on the sample surface. The galvanic current increases and the corrosion becomes worse as the water content in soil increases.