Three groups of experiments were carried out by using vernier sensor. Through layer by layer comparative analysis and evidence reasoning, it was proved that the dilute sodium hydroxide solution commonly used in the laboratory (with a concentration of about 3.84%) has a much greater ability to absorb carbon dioxide than saturated lime water, and the thinking model of carbon dioxide test and absorption was successfully constructed. This experiment is close to the teaching material. The data change process is carried out synchronously with the experimental process. The experimental data can be displayed in real time in the form of digital or image. Therefore, it can quantitatively assist chemistry teaching, and can also be confirmed with common qualitative experiments.