The invention relates to a control circuit for real-time supply of motor braking energy to an AC inertial load, including a motor main control circuit, a braking energy DC / AC dispatching circuit, specifically including a rectifier module PR1, an IGBT module PM1, a DC / AC module PW1, a motor Control module CU1, AC inertial load AL1, motor M1, encoder PG1, brake tube VT1, voltage sensor VS1, DC / AC module PW1, contactor K1, freewheeling diode D1, rectifier inductor L1, buffer inductor L2, rectifier capacitor C1, buffer capacitor C2. The invention can automatically convert the braking energy of the motor through DC / AC conversion and directly convert it to this kind of AC inertial electric load for power supply. The conversion and utilization efficiency of the braking energy of the motor in the invention is high, the energy saving effect is good, the cost is low, and the application is convenient. High reliability.