Defects play a vital role in improving photocatalytic performance. However, the specific influence mechanism of sulfur defects (DSS) on sulfide photocatalytic performance and stability is still unclear. In this work, an ingenious solvent-free self-overflow strategy is designed to introduce DSS into ZnS nanoparticles and explore the specific promotion mechanism of photocatalytic performance and photostability. The results indicate that the introduced DSS in ZnS nanoparticles can simultaneously boost the photocatalytic hydrogen production (PHE) performance and photostability of ZnS: the PHE rate of the defective ZnS can increase up to 21350.23 μmol·h -1 ·g -1 , which is roughly 4.7 times higher than that of pristine ZnS. Both experiments and theoretical calculationsshow that the enhanced photocatalytic performance could be attributed to the change of energy band position after introducing DSS. Specifically, the introduction of DSS can raise the conduction band (CB) position of ZnS to enhance the reducing ability of photogenerated electrons. Besides, the valence band (VB) position can also be raised to boost the light absorption ability of ZnS and restrain the photocorrosion by weakening the oxidation capacity of the photogenerated holes. The ingenious strategy and interesting mechanism in this job provide a simple artful tactic to fabricate other defective sulfide photocatalysts and open up a particular path to promote the photostability of the photocatalysts.