Harmful gas concentration monitoring system and method and server

The invention provides a harmful gas concentration monitoring system, a harmful gas concentration monitoring method and a server. The system comprises a harmful gas sensor, a signal acquisition module, a digital-to-analog conversion module and a BMC (Baseboard Management Controller) module, the signal acquisition module is used for acquiring a voltage signal of a harmful gas sensor currently located in a monitoring area in real time and sending the acquired voltage signal to the digital-to-analog conversion module; the digital-to-analog conversion module is used for converting the voltage signal into a corresponding digital signal to obtain voltage data of the harmful gas sensor and sending the voltage data to the BMC module; and the BMC module is used for determining a harmful gas concentration monitoring result of the current monitoring area according to the voltage data and generating a corresponding real-time monitoring log. The real-time monitoring log records the change condition of the concentration of