Abstract: To analyze 14C content in graphite of reactor retirement waste, a suit of making sample experiment system with high temperature catalysis and oxidation was designed. The treatment ability and working function of this system were confirmed partly in the lab. The results show that the catalysis and oxidation ability is 96% with 1 L/min gas flux and 800 ℃ oxidation temperature, and the ability of 2 mol/L NaOH solution absorption to CO2 is 99% (first absorption 67%, second absorption 32%). Determinating by fluid scintillation of CaCO3 solid powder suspended solution, the recovery rate is 99%.