Special sites such as petrochemical plants and hazardous chemical production and storage often have toxic and harmful gas diffusion and spread in case of safety leakage accidents. How to ensure the safety of emergency rescue personnel is currently a research hotspot in the field of emergency rescue. This article proposes a toxic and harmful gas risk monitoring and early warning system suitable for fire emergency rescue sites. The system is based on the existing emergency communication system and equipment of China's fire rescue teams, and realizes real-time perception, transmission, and processing of toxic and harmful gas concentrations around the body area of individual firefighters. Through grid based rescue sites and matching calibration with positioning data, the Reformer model is applied to predict and warn the spread concentration of toxic and harmful gases in the grid area, can provide data support for scientific command by rescue site commanders.