Psilocybin is a hallucinogenic indole alkaloid derived from mushrooms, which is metabolized into psilocin in vivo and exerts biological effects. Clinical studies have shown that psilocybin has the effect of relieving anxiety and depression in cancer patients. Due to its fast onset, significant therapeutic effect, and low addictive nature, psilocybin has the potential to break through the bottleneck of slow action and poor efficacy of existing depression drugs, bringing new hope for the treatment of severe depression and refractory depression. This article will review the pharmacokinetics, antidepressant mechanisms, and research progress of psilocybin, providing a reference for subsequent research.