This paper explores the hydrogen embrittlement sensitivity of pipeline steel under different hydrogen partial pressures to provide data support for the safe operation of natural gas hydrogen pipelines. The hydrogen embrittlement sensitivity of X60 pipeline steel base material and girth weld under different hydrogen partial pressure environments was studied. Slow strain rate tensile (SSRT) and in-situ gas phase hydrogen permeation tests were carried out at different hydrogen partial pressures of 0.6 MPa, 1.2 MPa, and 2.4 MPa. According to the tensile curve and fracture morphology, it is shown that with the increase of hydrogen partial pressure, the mechanical properties of the base material and girth weld gradually decrease, and the hydrogen embrittlement sensitivity increases. Compared with the base material, the girth weld has a higher hydrogen embrittlement sensitivity due to the coarse grains. When the hydrogen partial pressure reaches 2.4 MPa, the hydrogen embrittlement sensitivity of the girth weld reaches 19.3%, which is twice as high as the base material. With the increase of hydrogen partial pressure, the time for hydrogen diffusion in the girth weld to reach a steady-state is faster, the steady-state current density is higher, and the apparent hydrogen diffusion rate is higher, which further shows that the hydrogen embrittlement sensitivity at the girth weld is higher than that of the base material.