Experimental research on dynamic gas lock (DGL) suppression ratio is presented. Firstly, an experimental system of the extreme ultraviolet (EUV) vacuum DGL is designed; then the vacuum pumping system is designed detailedly, and the practical layout of the vacuum system is developed; moreover, the experimental steps are pointed out; finally the DGL experiments are carried out and results are analyzed to verify the theoretical model and simulation results of the DGL. Experimental results show that suppression ratio of the DGL increases gradually as the purge-gas flux increases when the dirty-gas outgassing is constant; suppression ratio of the DGL has nothing to do with the dirty-gas outgassing under the same conditions; and suppression ratio of the DGL increases slowly as the purge-gas molecular weight increases and the purge-gas flux and dirty-gas outgassing remain stable. The experimental research on DGL suppression ratio is helpful for the development of DGL in EUV lithography machine.