Herpes simplex virus type 1 (HSV-1) can cause fatal herpes simplex virus encephalitis (HSE), and some patients may experience severe neurological sequelae even with antiviral therapy. Effective suppression and clearance of HSV-1 infection rely on both innate and adaptive immune responses of the host, with T-cell activation and regulation playing a major role in adaptive immunity, while innate immunity also plays a crucial role in inhibiting virus replication and spread. This article summarized the immune response characteristics and mechanisms in HSE, outlined the protective and damaging effects of the immune system on the body, thereby providing insights for new mechanistic studies and the development of novel immunotherapies.