With rapid development of hydrological telemetry system in recent years, its market has been expanded with more and more con - cerned manufacturers and products. For the lack of unified data transmission protocols, different systems provided by different manufacturers are not compatible, telemetry terminals are not interchangeable, so that the system construction and operation management is very inconve - nient. Based on this situation , a new unified specification was established by the organization of competent authority. This paper expounded the principle and related technical measures in compiling process. It also explained the frame structure of the statute. Meanwhile, approaches of two character code, ASCII and HEX/BCD, were illustrated by instants. Under the current condition, it proposed how to boost unified specifica - tion, and put forward the relevant measures