The HETS-ALK-S Series aims to serve as an accurate, reliable and convenient platform for testing ALK electrolyzers. It mainly consists of the gas-water separation unit, gas concentration monitoring unit, gas cooling and drying, hydrothermal management unit, linkage pressure control unit, measurement control unit, and safety protection unit. Through online data monitoring and processing by the system platform, the performance, lifetime, reliability and safety of the electrolyzer under test can be analyzed. The series applies to the R&D, verification and EOL testing ofALK electrolyzers.