Abstract: To address the problems of low efficiency, poor consistency, and high radiation exposure risk associated with manual, sequential calibration measurements in the quality control of carbon-14 radioactive sources used in ambient particulate matter monitors, an automated activity measurement system was developed. The device integrates an automatic sample loading tray, a high-precision activity measurement unit, a sorting actuator based on stepper motors and suction tips, and intelligent control software. By using a dedicated algorithm, it enables rapid activity calculation and automatic pass/fail judgment, and physically sorts out nonconforming products. The system can process up to 100 radioactive sources in a single batch, achieving a gauge repeatability and reproducibility (R&R) value of 13.1%, a number of distinct categories (NDC) of 16, and a sorting accuracy exceeding 99.0%. Compared with manual operation, the efficiency is improved by 49.2%, while human intervention and radiation exposure risks are significantly reduced. The system realizes fully automated, high-throughput activity measurement of carbon-14 sources, greatly enhancing inspection efficiency and consistency, and providing reliable technical support for ensuring the accuracy of environmental monitoring data at the source.