Abstract: The B2 phase FeAl alloy was prepared by powder metallurgy method with iron powder and aluminum powder as raw materials. The electrochemical hydrogen diffusion behavior of B2 phase FeAl alloy was studied by electrochemical method. The results show that the pores in the prepared B2 phase FeAl alloy were few and small, and the segregation region with black and white stripe-like substructure similar to pearlite appeared in the microstructure. The aluminum content in the segregation region was higher than that in the unsegregated region. The stabilized hydrogen diffusion current density was slightly smaller than the limited hydrogen diffusion current density at different hydrogen current densities. The diffusion flux, effective diffusion coefficient and solubility of hydrogen in B2 phase FeAl alloy increased with the increase of cathode hydrogen charging current density. Under the action of cathode hydrogen charging current, the hydrogen desorption rate constant of alloy surface on the hydrogen charging end side was much larger than the adsorption reaction rate constant. Only a very small amount of hydrogen could be adsorbed to the surface and penetrated into the alloy, indicating that the occurrence of hydrogen embrittlement in the B2 phase FeAl alloy was relatively slow in the water vapor environment at room temperature.