Abstract: Wireless power transfer (WPT) technology, due to its superior safety and reliability, is widely applied in various fields. When used in high-voltage transmission line monitoring devices, it reduces safety hazards such as electric sparks caused by traditional live plug-in charging methods. However, the WPT technology in conventional transmission line monitoring equipment is typically open-loop controlled, leading to uncontrollable fluctuations in system output voltage in harsh and variable outdoor environments, which affects the performance and lifespan of monitoring devices. To address this issue, this paper adds a Buck-boost circuit to the receiver end of the WPT system and employs model predictive control (MPC) to ensure stable and fast tracking of the output voltage. By modeling and analyzing the new topology circuit and testing the performance of the model predictive control algorithm under different operating conditions, simulation results demonstrate that this topology and control algorithm can effectively control the output voltage of WPT and maintain voltage stability when input voltage and load vary, making it highly suitable for high-voltage transmission line monitoring.