Abstract: Dual-core phase-shifting transformer can effectively control the line voltage and power flow, optimize the distribution of power flow, and improve the power quality of the power grid. Aiming at the problems of voltage fluctuation and deviation of active distribution network caused by the high proportion of distributed power access, as well as the influence on the size, direction and balance of power flow, we studied the topology and working principle of dual-core phase-shifting transformers. Then, we analyzed the specific structures and functions of series transformers and excitation transformers, and sorted out the gear control strategies of phase-shifting transformers when they are applied to voltage regulation and power flow control. Finally, based on MATLAB/Simulink, we established a detailed simulation model to study the voltage regulation effect of the dual-core phase-shifting transformer, and compared the power flow control effects in three application scenarios of dual-line parallel connection, parallel power supply of two power sources, and multi-channel power supply in parallel. The simulation results show that the dual-core phase-shifting transformers can control the line voltage within a limited range of positions. Compared with the application scenarios of dual-line parallel connection and multi-channel power supply in parallel, the power flow balance effect is the best and the power flow deviation is the smallest when the two power sources are connected in parallel. This study provides a reference for the wide application of dual-core phase-shifting transformers.