Seawater hydraulic overflow valve

The invention discloses a seawater hydraulic overflow valve which comprises a valve body, a combination valve seat arranged at one end of the valve body, a valve core component and a spring accommodated in a valve cavity, and a spring seat arranged at the other end of the valve body, wherein the valve core component is arranged in the valve body and comprises a valve core and a ball seat for containing the valve core, the valve core and the valve seat are contacted to form a valve port, one end of the valve seat is a ball socket for positioning the valve core, and the other end abuts against the spring, the other end of the spring abuts against the spring seat, and a sealing ring is assembled on the periphery of the spring seat to form static sealing with the valve body; and the valve seat is limited through a gland on the end portion of the valve body, the center of the gland is connected with an adjusting screw rod through threads, and the position of the gland is adjusted by adjusting the adjusting screw rod to achieve limit adjustment of the spring seat, accordingly, set pressure of the valve body is adjusted. The seawater hydraulic overflow valve can serve as a constant pressure valve or a safety valve to work on a seawater hydraulic system, and has the advantages of being simple in structure, convenient to process, good in opening and closing performance and stable and reliable in working.