Automobile exhaust has become one of the important factors that affect atmosphere environment and cause environmental pollution. Therefore, it is necessary to do a good job of automobile exhaust detection. However, existing surveillance systems for such a poisonous gas still have some drawbacks like a limited network function, wiring complexity, a small signal coverage, poor compatibility. To overcome above disadvantages, this paper presents a master–slave wireless network monitoring system by integrating ZigBee and GSM technologies. The detected gas status from the Remote Detection Unit can be transmitted to Master Monitoring Station via self-organizing ZigBee network. The Master Monitoring Station connected with the Monitoring Server is to process the data received and thus send mobile phone real-time alarm information via GSM module. Simultaneously, the Monitoring Server can display the gas status and record it in the database online. Also, it can adjust gas warning level according to the temperature and humility of environment. Experimental results show that the proposed system is feasible in terms of stability reliability, self-organizing and wide area range, achieving the expected design goals in data acquisition and transmission, especially in simplifying equipment installation and wiring, improving system mobility and portability and remote monitoring.