Gas concentration adjusting device

The embodiment of the invention discloses a gas concentration adjusting device, which comprises a gas concentration detection module, a control module and a flow regulation module, wherein the gas concentration detection module is used for detecting the concentration of mixed gas and outputting corresponding detection voltage; the control module is connected with the gas concentration detection module, compares the detection voltage with a preset voltage, and controls the opening degree of the flow regulation module according to a comparison result; the flow regulation module changes the opening degree of the flow regulation module so as to adjust the flow of the gas output by each gas container; and the flows of the gases output by the gas container are different, and the concentrations of the mixed gases are different. By the adoption of the device, the requirement for the gas container for storing the gas with the calibrated concentration is reduced, the gas with the calibrated concentration can be provide