Pressure control mechanism

The invention provides a pressure control mechanism which comprises a shell, a first cavity, a second cavity and a third cavity which are communicated with one another are sequentially formed in the shell, and the first cavity is used for being communicated with equipment; the first valve body is provided with a first flange and a second flange, the first flange moves between the first cavity and the second cavity, and the second flange moves between the second cavity and the third cavity; the elastic assembly is located in the third cavity and arranged on the periphery of the first valve body in a sleeving mode, one end of the elastic assembly abuts against the second flange, and the other end of the elastic assembly abuts against the shell; the elastic assembly comprises a first elastic piece and a second elastic piece which are connected, and the rigidity of the first elastic piece is larger than that of the second elastic piece. According to the pressure control mechanism provided by the invention, the pr