This dataset represents the treatment process of leachate generated from landfill activities. The dataset is applicable to semi-humid regions (long-term average annual precipitation of 400--800 mm), and the treatment technologies mainly include filtration separation, centrifugal separation, sedimentation separation, neutralization, chemical precipitation, chemical coagulation, anaerobic hydrolysis, anaerobic biological filtration, stabilization ponds, constructed wetlands, and land treatment methods.