Abstract: With the widespread use of wireless devices, the semiconductor application market has placed higher demands on low-power encryption circuits. Reducing power consumption can extend the operating time and standby time of wireless devices, while encryption circuits ensure data transmission security. In the low-power design method, it is of great research significance to reduce the signal toggle rate by coding the signal. BI (Bus-Invert)1 coding technology can reduce the toggle rate of random signals. By introducing BI coding technology in AES encryption circuit and encoding input data, an improved low-power AES encryption circuit can be obtained. It is verified that compared with the original circuit, the average toggle rate of the ShiftRow, MixColumn, SubByte, and KeyExpansion sub-modules of the improved circuit is reduced by 68%, 42%, 50%, and 46%, respectively, and the dynamic power consumption is reduced 36.4%.