A wireless electric energy transmission system, wherein the system comprises a transmitter and a receiver, the transmitter comprises a DC/AC inverter circuit, a first inductor (L1), and a first capacitor (C1) that are connected in series, the receiver comprises an AC/DC rectifier circuit, a second inductor (L2), and a second capacitor (C2) that are connected in series, electric energy of the transmitter is transmitted to the receiver through electromagnetic induction between the first inductor and the second inductor, and the AC/DC rectifier circuit is configured to rectify the electric energy transmitted by the transmitter to the receiver; and the transmitter is configured to: detect a value of a resonant frequency of the transmitter; detect a value of a coupling coefficient between the transmitter and the receiver; obtain a value of a constant-voltage operating frequency of the transmitter through calculation based on the resonant frequency and the coupling coefficient; and control an operating frequency of the DC/AC inverter circuit based on the constant-voltage operating frequency obtained through calculation; and wherein the receiver is configured to detect an output voltage of the receiver; and the transmitter is configured to: determine that a value of a gain is not equal to a first threshold, wherein the gain is a ratio of the output voltage of the receiver to an input voltage of the transmitter; modulate, within a preset range, the constant-voltage operating frequency obtained through calculation, until the value of the gain is equal to the first threshold; and control the operating frequency of the DC/AC inverter circuit to be a modulated constant-voltage operating frequency. detect a value of a resonant frequency of the transmitter; detect a value of a coupling coefficient between the transmitter and the receiver; obtain a value of a constant-voltage operating frequency of the transmitter through calculation based on the resonant frequency and the coupling coefficient; and control an operating frequency of the DC/AC inverter circuit based on the constant-voltage operating frequency obtained through calculation; and wherein the receiver is configured to detect an output voltage of the receiver; and the transmitter is configured to: determine that a value of a gain is not equal to a first threshold, wherein the gain is a ratio of the output voltage of the receiver to an input voltage of the transmitter; modulate, within a preset range, the constant-voltage operating frequency obtained through calculation, until the value of the gain is equal to the first threshold; and control the operating frequency of the DC/AC inverter circuit to be a modulated constant-voltage operating frequency. determine that a value of a gain is not equal to a first threshold, wherein the gain is a ratio of the output voltage of the receiver to an input voltage of the transmitter; modulate, within a preset range, the constant-voltage operating frequency obtained through calculation, until the value of the gain is equal to the first threshold; and control the operating frequency of the DC/AC inverter circuit to be a modulated constant-voltage operating frequency. <EOS>