The structure that secretes renin is the paraglomerular granular cell, and the receptor of renin secretion is the dense plaque, which mainly senses the blood volume and sodium concentration of the human body, and will stimulate the secretion of renin when the human body’s blood volume is insufficient and the concentration of sodium ions is too low. The main function of renin is to convert angiotensinogen into angiotensin I in the blood, which can constrict blood vessels and raise blood pressure. Renin is an important part of the renin-angiotensin system, which is an important regulatory system in the human body, regulating the blood volume level of the human body, and can also play a role in regulating blood pressure. Renin secretion is regulated by various factors, such as when circulating blood volume decreases, sympathetic nerve excitation as well as dense plaque receptors and other excitations, it will activate the corresponding detrusor receptors, thus promoting the release of renin from parabulbar granule cells. Prompt medical attention is recommended in case of discomfort and renal disease.