The nature and concentration of sewage produced are different according to different cargo types in the cargo terminal.The sewage produced by bagged cargo terminals and storage yards is mainly initial rainwater，while that produced by unpacked cargo storage yards such as wood and stone is mainly runoff rainwater.The initial rainwater and the later clean rainwater can be divided by electric gate or natural switching.This paper collects the initial rainwater in the initial rainwater tank and discharges the later clean rainwater into the rainwater system.The runoff rainwater sewage is collected in a regulating sedimentation tank.According to the nature of sewage，the initial rainwater and runoff rainwater sewage should be treated by air flotation and coagulant sedimentation respectively.If there are reuse requirements，the treatment process of filtration and disinfection shall be added.