AbstractActive electronic states in transition metal dichalcogenides are able to prompt hydrogen evolution by improving hydrogen absorption. However, the development of thermodynamically stable hexagonal 2H-MoS₂ as hydrogen evolution catalyst is likely to be shadowed by its limited active electronic state. Herein, the charge self-regulation effect mediated by tuning Mo−Mo bonds and S vacancies is revealed in metastable trigonal MoS₂ (1T'''-MoS₂) structure, which is favarable for the generation of active electronic states to boost the hydrogen evolution reaction activity. The optimal 1T'''-MoS₂ sample exhibits a low overpotential of 158 mV at 10 mA cm⁻² and a Tafel slope of 74.5 mV dec⁻¹ in acidic conditions, which are far exceeding the 2H-MoS₂ counterpart (369 mV and 137 mV dec⁻¹). Theoretical modeling indicates that the boosted performance is attributed to the formation of massive active electronic states induced by the charge self-regulation effect of Mo−Mo bonds in defective 1T'''-MoS₂ with rich S vacancies.