The minimum ignition temperature is an important basis to determine whether the fuel air explosive has the phenomenon of fire channeling. The mixture of flammable liquid and air forms gas-liquid two-phase cloud. At present， the research on the minimum ignition temperature and the specific influence of cloud concentration， particle size and velocity on the minimum ignition temperature are still in a blank stage. In this paper， the research method of dust minimum ignition temperature is used for reference. With Godbert- Greenwald （G-G） heating furnace as the main test instrument， the minimum ignition temperature test system of gas-liquid two-phase cloud is established. On this basis， the cloud instantaneous concentration particle size test device is established. With ethanol as the experimental reagent， the particle size distribution of ethanol gas-liquid two-phase cloud was measured under the experimental conditions of 7000 g·m^-³ cloud concentration at the center of the heating furnace and 0.06-0.10 MPa fuel dispersion pressure. The effects of particle size distribution and cloud velocity on the minimum ignition temperature were analyzed and discussed. Under the concentration of 7000 g·m^-³， with the increase of pressure from 0.06 MPa to 0.10 MPa， the particle size decreased from 146.58 μm to 70.97 μm， the lowest ignition temperature of ethanol first decreased from 468 ℃ to 464 ℃， then increased to 476 ℃， and finally kept at 475 ℃. When the pressure is less than 0.07 MPa， the main factor affecting the MIT is the particle size， which decreases with the drop diameter. When the pressure is greater than 0.07 MPa， the main factor affecting the MIT is the flowing velocity. Since the velocity is constant， the minimum ignition temperature also stays stable.