A series of recyclable NiO/NaBr catalysts were prepared by supercritical hydrothermal syn-thesis for hydrogen production from formaldehyde steam reforming. Combined with XRD,N2 adsorption /desorption,SEM,XPS,H2-TPR,in situ DRIFTS and other characterization techniques,the phase struc-ture,specific surface area,microstructure,element valence,redox properties and steam reformingreaction transient of NiO/NaBr catalysts were analyzed. Results showed that 1% ~5% NiO/NaBr cata-lysts efficiently produced hydrogen. 2%NiO/NaBr showed the best hydrogen selectivity about 104% at450 ℃,and its formaldehyde conversion was close to 100%. The hydrogen production performance afterone-time regeneration could return to the fresh level. The NiO/NaBr catalyst had dense surface struc-ture and small surface area ( < 1 m2·g-1) ,which broke the limitation that small-surface-area catalystwas difficult to obtain high catalytic activity. The steam reforming of formaldehyde was a surface rapidreaction process. NiO was reduced to Ni without affecting the catalytic activity. NaBr could not only ad-sorb formaldehyde and form polyformaldehyde,but also help the catalytic maintain great low temperatureredox properties and hydrogen production performance.NiO/NaBr could not only adsorb formaldehyde and form polyformaldehyde，but also help the catalytic maintain great low temperature redox properties and hydrogen production performance．