The invention discloses a combined overflow valve with pressure regulating and pressure limiting functions, and belongs to the technical field of hydraulic overflow valves. The valve comprises a valvebody, a pressure regulating valve, a pilot valve, a pressure limiting valve and an electromagnetic emergency valve, wherein the valve body is provided with a flow channel, a valve element assemblingcavity, a liquid inlet i, a liquid outlet i and a liquid outlet ii, wherein one side of the pressure regulating valve cavity is communicated with the liquid inlet i, the other side is connected with the pilot valve through a flow channel, the pilot valve cavity is communicated with the liquid outlet ii, the pilot valve cavity is communicated with the pressure regulating valve spring cavity throughthe drainage hole, the spring pre-tightening force applied to the pilot valve can be adjusted by rotating the adjusting bolt, the pressure regulating valve is arranged above the pressure regulating valve and is coaxial with the pressure regulating valve cavity, the main valve element of the pressure-limiting valve is balanced by utilizing the pressure on the inner side and the outer side, and once one end of the pressure-limiting valve is released, the main valve element of the pressure-limiting valve can be quickly opened and released, so that the safety of the system is ensured. According to the combined overflow valve, the valve element can be effectively prevented from resonance, the pressure abnormity is automatically controlled, the valve body is reasonable and compact in structure,and the working stability of the pressure regulating valve is high.