In daily life, accurate gas detection is usually required in important scenarios such as air environment detection, fruit and vegetable ripening detection, and border inspection. Traditional gas detection methods include gas chromatography and mass spectrometry, but all of them have the disadvantages of complicated operation and long analysis time. Bionic electronic nose is a new type of gas detection method in recent years, which has the characteristics of fast response, high sensitivity, and good real-time performance, but the existence of internal gas chamber, sensor material, and the phenomenon of temperature drift will affect the accuracy and sensitivity of gas detection. In this paper, on the basis of imitating the internal structure of the nasal cavity of canine mammals, the basic design requirements of the bionic electronic nose are proposed, and three different structures are designed. The software Solidworks is used to construct a three-dimensional model and extract the fluid domain, establish a hydrodynamic model, and simulate and analyze the inlet and outlet process of the bionic electronic nose through the software Ansys Fluent, taking the contact effect between the gas and the sensor as an index, comparing the velocity cloud diagram, streamline diagram, and velocity vector arrow diagrams of the three designs of the internal cavities under the same flow velocity, and finding that the double inlet channel of the structure has the best effect. At the same time, using the combination of the upper computer and MQ series sensors for gas sensing experiments, it was found that the detection efficiency of the gas was increased by 20% by using the shape of narrow front and wide back combined with the gas infusion structure.