Dekang stand-alone monitoring system is a set of alarm system developed according to the requirements of metallurgy, petroleum, chemical industry, etc. The system consists of combustible and toxic gas detector, alarm control unit, monitoring software, network system, and power module and other accessories. The system is designed according to GB/T 50493-2019 ‘Petrochemical Combustible and Toxic Gas Detection and Alarm Design Specification’, which can realise the functions of on-site detection, centralized monitoring, alarm reminder and historical record, etc. It can timely detect all kinds of combustible, toxic and hazardous gas leakage at the site, and prevent the occurrence of safety accidents in the enterprise through sound and light alarms and other multilevel warnings, and guarantee the safe production.