Abstract: Accelerator mass spectrometry(AMS) is the most sensitivity measurement technique for the long-lived radioisotopes up to now and has been widely used in archaeology, geology, environment, physics and other fields. With the development of technology, the AMS devices are developing towards the miniaturization. The miniaturization of AMS device has been well applied. In this paper, the key technologies of AMS for long-life radionuclide high-sensitivity analysis are comprehensively discussed, and the characteristic technologies used in the miniaturized AMS system are systematically introduced. Finally, the devices and performances of two miniaturization AMS system developed by China Institute of Atomic Energy are discussed.