We developed an AIoT-based real-time multi-modal composite wearable sensor device to detect early signs of biological abnormalities in workers in ultra-high-risk field workers in shipbuilding, heavy industry, chemical plant construction, etc. and to prevent safety accidents such as hazardous gas leaks. Based on multi-layer bio-signal decomposition technology, we provide a data-based integrated worker safety management service that determines risks through analysis of workers’ individual movement patterns and biometric data and combines harmful gas detection technology using IoT sensor arrays.