The invention discloses an electrodynamic force supply highway traffic system and an electrodynamic force acquisition method. The system comprises a road network power accumulation station network which comprises a live line (201), null lines (202) and a plurality of road network power accumulation stations. The live line (201) is erected over a road, the null lines (202) are erected over the roador laid on the road, and the road network power accumulation stations are connected through a road network power supply circuit, provides electrodynamic force for electric vehicles running on the road through the line (201) erected over a road and leads current out to the null lines (202) erected over the road or laid on the road. The electrodynamic force supply highway traffic system and the electrodynamic force acquisition method have advantages that power supply of common electric vehicles is realized, high-voltage safety power consumption of the electric vehicles is realized, automatic accessing and releasing of the electric vehicles are benefited, and the requirement of the vehicles running on expressways can be met.