Abstract: The single cell hydrogen charging test and slow strain rate tensile test were carried out for the base metal and welding heat affected zone（HAZ） of DH36 steel, and the effect of the hydrogen charging current density on the hydrogen embrittlement sensitivity of DH36 steel was investigated by SEM characterization. The results show that when the hydrogen charging current density is 50 mA/cm², the hydrogen embrittlement sensitivity of the base metal and welding HAZ is the biggest; when the hydrogen charging current density continues to increase, the hydrogen embrittlement sensitivity of the base metal decreases slightly, while the welding HAZ decreases first and then increases. After hydrogen charging, the fracture mode of tensile fracture changes from ductile fracture to brittle fracture and the necking phenomenon disappears gradually, but some ductile fracture characteristics appear in the welding HAZ, when the hydrogen charging current density is 100 mA/cm².