To satisfy the needs of ultra-long standby and narrow space, a plan of wrist X-γ personal dosimeter was designed. According to the principle of the X-γ radiation incident on the semiconductor, the semiconductor detector is selected for detection, and the hardware design is completed with an ultra-low power MCU using a soft sealed package, to test the power consumption of the personal dosimeter by FLUKE 17B+ multimeter. The tests shows the maxim dose rate error is no more than ±20% and the maxim energy response error is no more than 25%. It can protect nuclear-related personnel avoid radiation injury and meet the requirements for dose management.