To solve the problem of large size and low stability of built-in wireless power transfer (WPT) systems in living organisms, this paper proposes a low-power wireless power transfer device with wireless communication capabilities. Firstly, the working principle and output characteristics of the LCC-S type compensation network used in this article were analyzed using circuit principles. Then, corresponding transmitting and receiving coils were designed using magnetic circuit design software, and the parameters of the transmitting and receiving coils were determined. Finally, a physical prototype of a micro constant voltage output WPT system was built, simulating the application scenario of wireless power transfer inside micro organisms. The designed system has a receiver diameter of 2.5 cm and an average thickness of 0.2 cm. When the distance between the transmitting and receiving coils is 3 cm (greater than the diameter of the receiver) and the frequency is 100 kHz, the received electrical signal is converted into a constant output voltage and wireless data transmission is achieved through the MQTT protocol.