An accelerator mass spectrometry measuring system is disclosed, including: an ECR high-current positive ion source subsystem; an injector subsystem; a high-current accelerator subsystem; a high-energy analysis subsystem; and a high-resolution detector subsystem; of which, the ECR high-current positive ion source subsystem, the injector subsystem, the high-current accelerator subsystem, high-energy analysis subsystem and a high-resolution detector subsystem are connected sequentially; the ECR high-current positive ion source subsystem is configured for generating high-current positive ions of multi-charge states; the high-current accelerator subsystem is configured for accelerating the high-current positive ions. The AMS system is high in beam, high in overall efficiency, and strong in how-down capability, and can greatly improve the abundance sensitivity of measurement.