Abstract: A method for improving the accuracy of oxygen concentration detection comprises the following steps: in a first step, when a gas to be detected enters a gas tube, the gas tube is connected to a detection channel and the gas enters the detection channel, the detection channel being a relatively-fixed sealed space only provided with a gas inlet and outlet; in a second step, initiate an ultrasonic wave generator located at one end of the detection channel, and initiate an ultrasonic wave receiver at the other end of the detection channel; and in a third step, in a fixed time segment ranging from 0.001 s to 0.01 s, a control chip records accurate reception time in which an ultrasonic sensor sends a startup to the ultrasonic wave receiver, and calculates the oxygen concentration in the time segment by using an calculation formula.