Visceral pain is the common clinical symptoms, the mechanism which causes visceral pain is very complex, with multiple neurotransmitter receptors in mediation role, protease activate receptors 4 (PAR4) is protease activate receptors (PARs) one of the family members, participate in multiple pathological physiology process. A recent study found that the activation of the internal analgesic action PAR4 has. PAR4 internal analgesic action is how to complete, and the molecular mechanism how, and other factors to pain receptors and what kind of contact is not clear. This paper is mainly expounds visceral sensation neural signal turned to mechanism and in pathology condition changes, understand the physiological and visceral pain producemolecular mechanism, remove visceral pain for ease of importance.