The invention discloses an electric driving system of an electric automobile. The electric driving system comprises a main automobile (1), a kinetic connection arm (3), an electric driving unit (2) and an intelligent host machine (4), wherein the intelligent host machine (4) comprises a host machine data acquisition controller (4-1), a host machine analog quantity input module (4-2), a host machine switch quantity input module (4-3), a host machine wireless bridge (4-6), a CPU (4-8), an electric driving information displayer (4-9) and the like; the electric driving unit (2) comprises a differential mechanism (2-11), an electric driving unit data acquisition controller (2-1), an electric driving unit wireless bridge (2-12), an electric driving unit analog quantity input module (2-2), an electric driving unit switch quantity output module (2-3), an electric driving unit analog quantity output module (2-4), a storage battery unit (2-5), a braking system (2-6), an electric motor (2-8), and the like. The electric driving system disclosed by the invention is low in energy consumption, environment-friendly, energy-saving, and flexible to charge, and does not influence short-distance running of the electric automobile; through the adoption of the electric driving system, the driving safety is guaranteed.