<p>This study develops an RVE model of hydrogen-containing TC4 alloy using CPFEM and XFEM, with parameters calibrated via first-principles calculations, to explore how hydrides influence crack initiation and propagation. The results show that hydrides have a mixed distribution, consisting of <i>β</i> phase-adjacent and plate-like hydrides within the <i>α</i> phase. Microcracks preferentially nucleate within hydrides at <i>α</i>/<i>β</i> phase boundaries, coalescing into intergranular cracks. Crack propagation tends to follow the hydride/<i>β</i> phase interface. Additionally, the presence of numerous hydrides in the <i>α</i> phase accelerates microcrack coalescence, ultimately resulting in transgranular fracture failure. This research contributes to filling the gap in simulation within the field and reveals the critical mechanisms by which hydride acts as both a crack initiation source and dominant propagation path. It offers valuable insights into the fracture mechanisms of hydride-containing titanium alloys, contributing to the design of more durable materials.</p> Graphical abstract <p></p>