Accurately acquiring the resistance of the sensor is always important for the quantitative recognition of mixed gases using metal oxide semiconductor. In this work, a SnO2 gas sensor was designed, a gas sensor test circuit was developed, and PID temperature controlPID temperature control technology was employed. On the base, the surface temperatureTemperature of the prepared sensor can be ensured unaffected by external factors, and the accuracy of resistance testing can be guaranteed. It was found that at 250 °C, the sensor resistance exhibited ohmic natures when the current through the material is below 4.34 μA. Conversely, when the current was above this current thresholds, the resistance decreases. Furthermore, it was found when the operating temperaturesTemperature were increased from 250 to 370 °C, the current thresholds were also increased to 22.04 μA. The findings in this work are beneficial for improvingNon-ohmic behavior the quantitative recognition of mixed gases using metal oxide semiconductors.