The presence of hydrogen in steels causes catastrophic embrittlement. However, the difficulties to observe the hydrogen and associate its influence with certain microstructure limit the advance of our understanding in this topic, especially for the origin of hydrogen embrittlement within pipeline steels. We therefore developed a method combining cryogenic atom probe tomography and micromechanics to correlatively study hydrogen distribution and the embrittlement initiation in pearlite, respectively. We ex-situ charged the samples with hydrogen and observed its distribution and the deformation around cementite/ferrite interfaces. These efforts lead to the confirmations of the absences of hydrogen at the interfaces and their failure due to hydrogen, suggesting the hydrogen-enhanced local plasticity in ferrite was the affecting mechanism, instead of the interfacial hydrogen-enhanced decohesion. We also observed hydrogen trapping at the interior of cementite, not the interfaces. These results advance our understanding of hydrogen behaviour in pearlitic pipeline steels for hydrogen transmission applications.