The invention provides an environmental monitoring method, an environmental monitoring device, an environmental monitoring system and a server and belongs to the environmental monitoring technical field. According to the method, after an area to be monitored is divided into a plurality of functional areas based on preset natural conditions and social and economic environment requirements, the social and economic factors, natural meteorological factors, the total quantity and concentration of environmental pollutant emissions of each functional area are obtained; feature analysis is performed on the total quantity and concentration of the environmental pollutant emissions of the functional areas, so that feature analysis results that characterize the change of the quantity and concentrationof the environmental pollutant emissions are obtained; social and economic factors and natural meteorological factors related to the feature analysis results are analyzed, and relations between the social and economic factors and the natural meteorological factors are also analyzed; and corresponding levels of environmental early warning thresholds are set according to the respective environmental quality requirements of the functional areas, so that early warning prompts can be obtained. The environmental monitoring method, the environmental monitoring device, the environmental monitoring system and the server are of great significance for regional environmental monitoring and are more effective in regional environmental monitoring.