Extremely low frequency pulsed electric field could arouse a comparatively intense reaction on physiological characteristics of plant cells, so the effect of the extremely low frequency pulsed electric field on crops drought resistance is very worthy to be studied. The delayed biophoton emission of cells, as a kind of life information, can reflect the changes of cellular physiological state. In order to study the influence of the extremely low frequency pulsed electric field on drought resistance of plants seedlings and its mechanism, the PEG-6000 solution with the osmotic potential of -0.1 MPa was used to simulate drought conditions, the germinating maize was treated by the extremely low frequency pulsed electric field at 100 kV/m, frequency 1 Hz and pulse width 80 ms, the changes of the delayed biophoton emission from maize seedling roots under osmotic stress were discussed. The results show that the changes of the kinetic parameters about delayed biophoton emission such as the initial photon number I0, coherence time τ and decay factor β decrease volatility. The changes of the kinetic parameters about delayed biophoton emission of maize seedling root treated by extremely low frequency pulsed electric field are the same, but, the value of these parameter increase significantly in comparison with the control. The analysis indicates that the extremely low frequency pulsed electric field treatment can raise the level of the metabolic level of cell and improve tissue order, the interactions between functional molecules in cells is enhanced. The results of this paper provide a reference for explaining clearly the effect of extremely low frequency pulsed electric field on drought resistance of plants seedlings and its mechanism.