Abstract: The effect of spatial electric field on soil moisture around barley root and barley growth under different pole distance (2.5, 2.0, 1.5 m) were studied in this paper. The results indicated that soil evaporation around barley root was restrained effectively in sunny day when the positive electric field was applied. If the field voltage and interval time are constant, the electric field intensity will be different under the different pole distances, and the effect of boosting plant growth will be different by restraining evaporation and moisture. The soil evaporation restrained effect was the best under a pole distance of 2.0 m. It also proved that spatial electric field can increase the weight of seeding and promoted the growth of barley height, which are increased by 26%-53% and 24%-68%, respectively, compared with the electric field in atmosphere, the best pole distance is 2 m for the plant growth. It shows that the appropriate positive electric field can restrain soil evaporation and promotes plant growth.