The existing wireless energy transfer systems are suitable for gastrointestinal robot that have low energy transmission efficiency, low received power, and poor location uniformity of received energy, which cannot meet the energy requirement of new gastrointestinal robots with complex functions. In this article, a new type of C-shaped combined transmitting coil structure is proposed. The magnetic flux density of the power supply unit is analyzed by finite element simulation, and position uniformity, determine the experimental optimization range of the coil pair spacing in the power supply unit group. Finally, an experimental platform is established to optimize the coil pair spacing distance in the power supply unit, and the design is evaluated and verified through the energy transmission efficiency of the system, the received power, and the position uniformity of the received power. Experimental results show that when the coil pair spacing distance is 150 mm, the received power at the center position is 1 165. 34 mW, and the energy transmission efficiency of the system is 6. 08% . The average power of the system is about 1 100 mW, the average energy transmission efficiency is over 6% , and the average position uniformity of the received power is 94% . By introducing a new type of C-structure magnetic core and adopting a combined coil structure in which only one power supply unit group works at the same time, the received power and energy transmission efficiency of the system are greatly improved, and the position uniformity of received energy is high.