High sensitivity and high-selective gas transducer

The invention discloses a high-sensitivity and high-selectivity gas sensor, comprising a gas pump, a gas sensing element, a sample chamber, a filter, a control valve, a gas inlet and a gas outlet. The gas sample is sent to the gas sensing element through the gas pump via the gas inlet to go through a first measurement; and the measured value comprises the measured gas and the contribution of interference factors. The interference factors comprise the environment, the gas sample temperature, humidity, pressure, airflow, interference gas and the like. The gas after the first measurement goes through the filter to remove the measured gas and then return to the same gas sensing element for a second measurement; and the measured value comprises the contribution of other interference factors excluding the removed measured gas. The difference between the two measurements serves as the measurement result for the measured gas, so that the contribution of the measured gas is retained, and the impact of interference gas, airflow, temperature, humidity and pressure and other factors is eliminated so as to achieve high sensitivity and high selectivity detection.