Dangerous gas detection method

The invention relates to the technical field of gas detection, in particular to a hazardous gas detection method, which comprises the following steps of: electrifying a measuring instrument, and acquiring an AD (Analog to Digital) value through a gas sensor; the method comprises the following steps: dividing measured AD data into four parts of period, trend, period and unstable factors according to different processing modes and a time sequence; processing a trend part, and correcting data causing data variance overrun in a period; abnormal data fluctuation caused by unstable factors is identified, and the segment of data is rejected; the unconventional step change of the data is solved by periodically carrying out mean value calculation on the data; a temperature and humidity sensor is introduced to measure numerical values, the reasonability is judged by comparing with a clock, and whether temperature and humidity compensation calculation is added is determined; and converting the AD value processed by the