Erinacine A, a cyathane diterpenoid derived from the medicinal and edible fungus Hericium erinaceus, is increasingly recognized for its potent neurotrophic and neuroprotective properties. It demonstrates significant therapeutic promise for neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease, primarily by stimulating the synthesis of nerve growth factor (NGF). However, the clinical applicability of erinacine A is currently restricted by its low yield from natural sources and high production costs. This challenge has spurred significant research focused on optimizing its production. This review provides a comprehensive overview of the current advancements in the fermentation-based preparation of erinacine A, including both liquid and solid-state cultivation techniques. Furthermore, we summarize its diverse biological activities, spanning neuroprotection, anticancer, and anti-inflammatory effects, and detail the recent discoveries elucidating its complex biosynthetic pathway. This consolidated overview offers insights into strategies for enhancing its production and supports its ongoing development as a therapeutic agent.