In this study, the effects of hydrogen concentration on hydrogen permeation and stress corrosion cracking behavior in 80SS low-alloy tubing steels in a saturated CO2 simulated produced water environment was explored by electrochemical hydrogen permeation, slow strain rate tension and stereo microscope, SEM methods. The results show that the acidity and the hydrogen permeation parameters i^∞, D and C_0^H were both increasing with the raise of the concentration of H+, which contributes to the diffusion behavior of hydrogen atoms. Since the synergistic effect of tensile stress and hydrogen atom, the fracture time of 80SS low alloy steel is reduced by nearly 50% compared with the tensile in air, and the change is occurred to ductile fracture to brittle fracture. As the hydrogen concentration of the solution increases, the mechanical damage of the steel and the stress corrosion sensitivity strengthen. Before and after pre-charged hydrogen the index Iδ changed from 3.16 to 8.49 when 80SS steel is stretched in a medium containing saturated CO2. Pre-charged hydrogen promoted the stress corrosion cracking sensitivity of the sample. When stretched in saturated CO2 produced water containing 1% HAc, the microscopic morphology before pre-charged hydrogen showed a river pattern with quasi-cleavage fracture characteristics. Discontinuous cracks and small pores are distributed with fiber area of 80SS steel of the pre-charged hydrogen. Compared with before pre-charged sample, pre-charged hydrogen improved the plastic properties of the steel and reduced the stress corrosion cracking sensitivity of the steel.