Abstract: To achieve safe and reliable intelligent supervision throughout the entire life cycle of industrial Cobalt-60 radioactive sources, this study aims to establish a dual marking system with “machine-readable automatic identification as the primary method and human-assisted judgment as the supplementary method.” It focuses on solving the core challenge of ensuring the long-term reliability of the machine-readable identifier under extreme environmental conditions. An intelligent marking method based on ultrafast laser direct fabrication of topographic Data Matrix codes on the end plug surface prior to source encapsulation is proposed. A three-stage experimental scheme was adopted: the first stage involved picosecond laser parameter screening on 60 simulated 316L stainless steel samples; the second stage conducted head-to-head environmental tests, including 800 ℃ heat resistance and simulated underwater reading, on six real end plugs; the third stage verified the “zero-damage” effect of the optimal process on material integrity via optical microscopy (OM) and metallographic analysis. A topographic DM code measuring 6.5 mm×6.5 mm with a depth of (80±10) μm was successfully fabricated on an end face of \phi 11.1 mm. The code quality reached Grade A according to ISO/IEC 29158:2025. The mark withstood an 800 ℃ thermal shock, maintained a 100% automatic reading rate in simulated underwater conditions, and introduced no microcracks while exhibiting an extremely small heat-affected zone. This study constructs a dual marking technical solution centered on a picosecond laser topographic DM code, compatible with traditional human-readable markings. The solution involves machining and verification before encapsulation, ensuring material safety and providing a reliable technical pathway for “physical-identity to digital-twin” supervision of radioactive sources. Furthermore, the established methodological framework lays an evaluation foundation for integrating higher-performance femtosecond laser processes in the future.