The nature of soil pollution—cumulative, hidden, latent, irreversible—makes it essential that urban soil pollution should be closely monitored and prevented. However, traditional monitoring methods cannot perform real-time pollution monitoring and have limited data processing capabilities. To address this issue, we aim to develop a pollution prediction and early warning system capable of real-time online monitoring, processing, and analyzing urban soil pollution data. In this paper we report the development of a monitoring and data visualization system based on microservice framework Spring Cloud Alibaba, whereby integrating the EMQX platform soil data are successfully collected and stored. Additionally, we develop a WebGIS module that interfaces with Geoserver—this module utilizes OpenLayers to render maps and soil element concentration charts, enabling the monitoring and visual analysis of soil conditions. We believe with breakthroughs in sensor technologies relating to chemical monitoring, real-time online monitoring, processing, and analysis of soil pollution data through Internet of Things (IoT) can be achieved. The IoT monitoring and visualization system has been tested and its effectiveness in identifying pollution changes, predicting trends, and devising effective prevention and control measures are demonstrated. Most importantly, practical applications confirm the system's notable advantages in enhancing the timeliness of soil pollution prediction and early warning.