The invention discloses an electric car wireless charging closed-loop control system based on a differential inductor. The electric car wireless charging closed-loop control system comprises a primaryside unit placed on the ground and a car-mounted secondary side unit. The primary side unit comprises an inverter circuit, a compensating circuit, a primary side resonance capacitor, a primary side power coil, a differential inductor coil and an MCU. The secondary side unit comprises a secondary side power coil, a secondary coil resonance capacitor and a rectifying circuit. The differential inductor coil can measure the current phasor of the secondary side power coil in a non-contact manner, and interference caused by primary side shielding. Output voltage of the differential inductor coil and primary side power current are sampled and calculated through the MCU, and serve as the feedback quantity of closed-loop control to be compared with the given quantity, a control signal is generatedby a PI adjustor, and the switch duty ratio of the compensating circuit is controlled; and then the reflected impedance of the compensating circuit on the primary side is changed. When the load changes, a primary side compensating network is adjusted to achieve impedance matching and self-tuning, and maximum power and efficiency of wireless charging are kept.