Abstract: Temperature and hydrogen-containing states are important factors affecting fatigue crack growth behavior and tensile fracture characteristics of Zr-Sn-Nb zirconium alloy welded joints. Specimens with different hydrogen-containing states were prepared by electrolytic hydrogen charging and vacuum diffusion annealing, and fatigue crack growth tests and tensile fracture surface analyses were conducted at room temperature and 360 ℃. With the extension of hydrogen charging time, hydride precipitation in the weld zone and base metal becomes denser. At room temperature, the da/dN–ΔK curves of hydrogen-containing specimens are generally located in a higher crack growth rate region, indicating a decrease in fatigue crack growth resistance of the joint. At 360 ℃, crack growth behavior is still governed by ΔK; however, the Paris parameters of specimens with different hydrogen-containing states fluctuate with temperature and hydrogen content, suggesting that crack growth behavior is jointly affected by hydride distribution, weld microstructural inhomogeneity, and crack propagation path. Fracture surface analysis indicates that an increase in hydrogen content increases brittle features such as quasi-cleavage facets, flat fracture surfaces, and secondary cracks. Under the 360 ℃ condition, plastic deformation features, including dimples, microvoids, and tear ridges, increase. Overall, an increase in hydrogen content promotes fatigue crack growth and enhances the fracture embrittlement tendency of the joint, whereas the high-temperature condition at 360 ℃ weakens hydrogen-induced embrittlement characteristics to some extent.