Hyperbaric oxygen (HBO) therapy is of clinical utility in patients with transient cerebral ischemia. The investigatory study was to identify the potential regulatory mechanism of HBO treatment on neuronal injury and neurological function recovery in rats with intracerebral hemorrhage (ICH). Firstly, the rat model of ICH was established by collagenase, and the experimental rats were treated with HBO at 2.5 absolute atmospheres for 60 min each time. Next, lentivirus interfering with microRNA (miR)-204-5p or chloride channel protein 3 (CLCN3) expression was injected via the tail vein. Afterward, neurological function assessment was conducted, serum S100β and NSE contents were detected by enzymer-linked immunosorbent assay, and pathological conditions of brain tissue were observed by hematoxylin-eosin staining. Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling staining was used to detect neuronal apoptosis. The results showed that HBO alleviated neuronal injury and neurological function recovery in ICH rats and reduced serum S100β and NSE content (all P<0.05). At the same time, overexpressing miR-204-5p or depleting CLCN3 further promoted the therapeutic effect of HBO on ICH rats (all P<0.05), while silencing miR-204-5p or elevating CLCN3 did oppositely (all P<0.05). In conclusion, HBO alleviates neuronal injury and neurological function recovery in ICH rats by silencing miR-204-5p-targeted CLCN3.