Abstract: Based on the TCAP hydrogen isotope separation principle, a new glove-box-size protium-deuterium separation device was designed. The separation column contained Pd/K composite is heated by helixal resistance heater, and is cooled by -50 ℃ ethanol cycled by a low-temperature thermostat. A SIEMENS PLC module is used to control the separation process according to the loaded program. With the optimized parameters, the separation efficiency was examined under the production conditions. The experimental results showed that 0.25 hour was needed for a single heating-cooling cycle, and the repeatability was good. Under the production conditions, the production efficiency was 8.7 mL/h, and 99.5% deuterium was obtained from the 80%(D purity) H-D mixture. A good D enrichment effect ( D purity in product reached 99.0%) was also observed when a low D content H-D feed（D%=20%）was used.