A dust devil is a weather phenomenon caused by small cyclones in the near-surface gas layer that make sand or other small objects roll up with the wind. At 11∶10 on October 27, 2011 and at 11∶12 on September 13, 2015 respectively, two strong dust devil weather events that occurred in Shanghai (Beijing time, the same below) caused different levels of disasters. Both dust devils occurred in the greenhouse area, the nature of the underlying surface of which is very different from that of exposed ground in the arid area and cement asphalt road surface in the city. Therefore, it is necessary to understand the cause. In this paper, the two dust devil processes are analyzed by using data from conventional weather maps, temperature logarithmic pressure maps, five-story tower wind and temperature below 100 m, microwave radiometers, and automatic weather stations in greenhouses, etc. It was found that no obvious super-adiabatic phenomenon was detected in the conventional sounding, but the vertical profile of the surface layer temperature observed by the tower combined with data from the microwave radiometer and the automatic weather station revealed that the near-surface gas layers were both equipped with super adiabatic conditions when the dust devils occurred. The mean vertical lapse rate of temperature γ before and after the occurrence of dust devils (10∶00—12∶00) reached 1.58 ℃/100 m, and the maximum value reached 2.33 ℃/100 m, which is more than twice the dry adiabatic lapse rate. The swirling and convergence characteristics of the 10 m, 30 m, 50 m, and 70 m near-surface wind fields obtained from the ten tower wind measurement networks in Shanghai revealed the source of angular momentum of the dust devil swirling. By analyzing the weather conditions of 500, 700 and 850 hPa, the large-scale circulation conditions favorable to the occurrence of dust devils are discussed to provide reference for dust devil forecasting. Finally, a preliminary view of the mechanism of the occurrence of the two dust devils in the greenhouse area rather than in the natural farmland is proposed for further discussion.