Revealing the micro-and meso-scale hydrogen?induced crack propagation mechanism of high-strength pipeline steel holds significant engineering value for ensuring the safety of hydrogen energy transportation. In this study, a ferrite-cementite interface model with Bagaryatskii crystallographic relationship was established for the pearlite structure formed by eutectoid ferrite (α-Fe) and cementite (Fe₃C) in ferrite?pearlite pipeline steel. Combined with Voronoi polygon polycrystalline model and cohesive zone model, the effects of hydrogen atom number fractions, grain size and cementite termination surface on the mechanical properties of pipeline steel in a hydrogen environment were systematically analyzed. The results indicate that at the micro scale, with the increase of hydrogen atom number fractions, the critical interfacial tension of pipeline steel decreases obviously, which decreases by about 3.10% and 7.50% respectively at 2.5% and 5.0% hydrogen atom number fractions, and the fracture energy also shows a downward trend. The order of cementite termination surface according to crack resistance is C-Fe > C-C > Fe-Fe > Fe-C. At the meso-scale, the increase of hydrogen atom number fractions (5.0%) leads to a decrease of 8.39% in the critical stress intensity factor（K_IC） and an increase of 12.06% in the crack length. When the grain size is refined from 16 μm² to 4 μm², the K_IC increases by 31.38% and the crack length decreases by 17.30%. The influence of the termination surface is consistent with the microscopic results. This research provides a theoretical reference for the intrinsic safety evaluation and adaptability analysis of ferrite?pearlite pipeline steel in hydrogen environment.