Abstract: Taking X65 pipeline steel as the research object, electrochemical hydrogen charging, slow strain rate tests (SSRT), combined with microstructure observation and tensile fracture morphology analysis was adopted. A double electrolytic cell structure was used to study the hydrogen permeation behavior. The focus was on exploring the effects of hydrogen charging current density and hydrogen charging solution temperature on hydrogen diffusion coefficient and hydrogen content. The relationship between hydrogen diffusion coefficient and temperature was determined, and the diffusion activation energy and diffusion pre-exponential factor of hydrogen atoms in X65 pipeline steel were obtained. The results show that after hydrogen charging, the yield strength and tensile strength of X65 pipeline steel changed slightly, while the elongation after fracture decreased significantly, the hydrogen embrittlement index was 34.80%, indicating severe hydrogen damage. As the hydrogen charging current density increased from 10 mA/cm² to 50 mA/cm², the steady-state current density, hydrogen diffusion coefficient, and hydrogen diffusion flux increased, while the diffusible hydrogen concentration decreased. When the temperature rised from 303 K to 343 K, the hydrogen penetration time shortened, and the steady-state current density, hydrogen diffusion coefficient, and cathode-side hydrogen concentration all increased. The diffusion activation energy of hydrogen atoms in X65 pipeline steel was 7 394.25 J/mol, and the diffusion pre-exponential factor was 1.85×10^-4 cm²/s. The relationship between hydrogen diffusion coefficient and temperature conformed to the Arrhenius equation.