The invention discloses a device and a method for crop planting experiments based on exposed environment and a power frequency electric field. The device comprises two pole plates, a power frequency power unit, a supporting suspension unit, and a control unit. The two pole plates are a lower pole plate arranged under crops and an upper pole plate which is arranged above the crops and is parallel with the lower pole plate. A power frequency electric field is formed between the upper pole plate and the lower pole plate through a power frequency voltage unit. The supporting suspension unit is used to suspend the upper pole plate above the crops. The control unit is used to control electric field intensity of the power frequency electric field. The device also comprises a water spraying unit used to simulate rainwater irrigation, and a light supplementing unit used to supplement light. The method comprises: arranging the lower pole plate under the crops, and arranging the upper pole plateparallel with the lower pole plate above the crops; forming the power frequency electric field between the upper pole plate and the lower pole plate through a power frequency high-voltage source; through the control unit, controlling output voltage of the power frequency high-voltage source, to adjust power frequency electric field intensity.