Abstract: The efficiency of wireless power transmission is influenced by switching frequency and resonant parameters. The adoption of tuning device may realize wireless power encryption transmission (WPET) and avoid power theft by unauthorized users. However, the traditional core regulated inductance tuning device has large control losses. Therefore, a parallel permanent magnet bias variable inductor (PMⅥ) is proposed in this paper. With finite element simulation analysis and related experimental verification, the regulation efficiency of the parallel scheme is more than 3 times that of the traditional scheme, and the fluctuation range affected by the main coil is less than 20% of the traditional scheme, which greatly improves the performance of the adjustable inductance. In addition, by analyzing the frequency sensitivity of resonant network, a set of WPET system based on PMⅥ is designed and built. The experiments of the WPET system show that the power of the unauthorized and stolen ends is suppressed to less than 5% and 10% of the authorized end respectively, which has proved the effectiveness of the variable inductor work and the anti-power-theft effect of the WPET system.