As a reactive alloy， the TiZrNbTa refractory high-entropy alloy exhibits excellent mechanical properties and energy release characteristics， However， due to the high melting points and significant differences among its constituent elements， the liquid–solid two-phase region is relatively wide， making it difficult to achieve large-scale forming via traditional casting processes. Powder metallurgy technology， as an effective means for preparing large-sized alloy components， offers a feasible approach to overcome this bottleneck. For this purpose， this study systematically investigates the hydrogenation and dehydrogenation processes of TiZrNbTa refractory high-entropy alloy powders. The results indicate that after hydrogenation at 550 ℃ under 0.25 MPa hydrogen pressure for 2 hs， the TiZrNbTa alloy ingot undergoes hydrogen-induced embrittlement， transforming from a Body-centered cubic （BCC） solid solution structure into metal hydrides such as ZrH₂， TiH₂， and （Nb， Ta）H. The irregular hydrogenated powder obtained via mechanical crushing has a median particle size （D₅₀） of 11.13 μm， with hydrogen and oxygen contents of 1.823% and 0.111%， respectively. Subsequently， dehydrogenation at 450 ℃ under vacuum for 1.5 hours yields TiZrNbTa refractory reactive alloy powder with a single-phase BCC solid solution structure. Its hydrogen and oxygen contents are 0.028 % and 0.121%， respectively， with a significantly narrowed particle size distribution and a reduced median particle size （D₅₀） of 5.67 μm， indicating that the hydrogenation-dehydrogenation process is an effective method for preparing TiZrNbTa refractory high-entropy alloy powder with low oxygen-contaminated and suitable particle sizes.