Currently

there is an extreme lack of experimental study on the latent heat effect of soil water vapor at high temperature around world

which restricts the full acknowledging of soil thermal characteristics at high temperature. Through the thermal conductivity test of three different soils at high temperature

the change of soil water vapor latent heat effect and water vapor transport enhancement factor η was discussed and analyzed. The results of test indicates that the latent heat effect of water vapor is generated inside the soil under the effect of temperature gradient

and the higher the temperature

the more obvious the phenomenon. The latent heat effect contribution caused by high temperature has obvious peak value and there is lag phenomenon.The water vaporization enhancement factor η is more dependent on soil texture and saturation

but the law of value is still unclear.