The psychoactive properties of cannabinoids are well known, and there has been controversy about whether cannabinoids can be used for therapeutic purposes worldwide.Δ9-tetrahydrocannabinol(tetrahidrocannabinol, THC), the main psychoactive substance in cannabis, its neurological mechanism has not been discovered until recently, and its neurological mechanism of action is still not fully understood. The blood-brain barrier(blood-brain barrier, BBB) is a very important barrier structure to protect the brain and is the first line of defense against foreign substances entering the brain. THC's lipophilic nature and its interaction with the endocannabinoid system make it more likely to act on the BBB. In this paper, we review the neurotoxic effects of THC, focusing on the effect and mechanism of THC on the BBB, and provide a theoretical basis for elucidating the neural mechanism of THC.