The invention provides an electric main driving system for a 1000kW power level pure electric alternating current driving switch engine. The electric main driving system comprises a first voltage sensor, a second voltage sensor, a third voltage sensor, a first resistor, a second resistor, a first power battery pack, a second power battery pack, an inverting module, a traction motor, a first current sensor, a second current sensor and a third current sensor, wherein the inverting module comprises a chopping branch circuit and a three-phase inverter circuit and can be used for realizing charging and discharging adjustment for the engine under different working conditions. A modularized and opening power battery pack system is established according to the invention; two sets of identical interchangeable lithium iron phosphate power storage battery packs are adopted as the power source of the engine; the provided coverage scope of energy is 500-1200kW; the electric main driving system can be adjusted according to the practical use condition of the engine and the requirements of the user.