The upper leaves of flue-cured tobacco cultivar K326 were used as materials, and the sensors were used to monitor the leaf gap wind speed, temperature and relative humidity of the upper leaves which baked after stem harvest(harvested with stem) and conventional harvest. The main factors affecting the leaf gap wind speed were screened by correlation analysis and stepwise regression analysis. Path analysis was used to analyze the dominant factors affecting leaf gap wind speed in different baking stages and in the whole baking process with the two harvesting methods. The results showed that the wind speed of leaf gap in each baking stage with stem harvest was higher than that with conventional harvest. The wind speed of leaf gap increased rapidly in the later period of color fixing. The dominant factors affecting the leaf gap wind speed with conventional harvest and stem harvest in each baking stage were water vapor pressure deficit(yellowing stage), main vein water content(color fixing stage), temperature(stem drying stage) and water vapor pressure deficit(yellowing stage), humidity(color fixing stage), temperature(stem drying stage). The dominant factor affecting leaf gap wind speed with the two harvesting methods during the whole baking process was water vapor pressure deficit, and the decision coefficients Ri2 were 0.962 and 0.877 respectively. The fitting results of water vapor pressure deficit and leaf gap wind speed during the whole baking process showed the best fitting effects for conventional harvest and stem harvest were exponential function and linear function, respectively, the Ri2 were 0.977 and 0.971, respectively. The cubic spline function of leaf gap wind speed and water vapor deficit in each baking stage was constructed. Except for the yellowing stage with stem harvest, the fitting effect was good, and the R2 was above 0.800. There is a big difference in the change of leaf gap wind speed between the two harvesting methods during the baking process. The dominant factors of leaf gap wind speed in the color fixing stage are different. The baking process can be adjusted to improve the leaf gap wind speed environment.