The invention discloses a main wiring system of an electric automobile charging station system. The main wiring system comprises a three-phase transformer, an alternating-current bus, a rectifier, a direct-current bus, a direct-current charging pile and an electric automobile. After voltage reducing and isolating are conducted on a charging station alternating-current inlet wire through the three-phase transformer, the charging station alternating-current inlet wire is connected with the charging station alternating-current bus which is connected with the rectifier, after rectification is conducted on the alternating-current bus through the rectifier, the alternating-current bus is connected into a charging station direct-current bus, the direct-current charging pile is connected with the direct-current bus, the direct-current charging pile is connected with the electric automobile, and electric energy is provided for the electric automobile. Due to the power supply structure that the rectifier is connected in a distributed mode, direct-current bus power supply is adopted, and a large-power direct-current solid-state switch is adopted, on the basis that the technological difficulty and the cost of the rectifier are not increased, the conflict between the equipment utilization rate and large-current charging is removed, and a solution is provided for fast charging.