The invention discloses a balance valve with secondary pressure overflow, comprising a main valve body. The main valve body is provided with an oil port A, an oil port B and an oil port T and is internally provided with a main valve cavity and a pilot valve cavity, wherein the oil port A and the oil port B are communicated with the main valve cavity, a main valve core, a pilot valve core and a spring are arranged in the main valve cavity, a control valve core is arranged in a pilot valve cavity, and a secondary pressure overflow mechanism is also arranged in the main valve body and comprises a pressure regulating valve core, a right containing cavity of the pressure regulating valve core, a left containing cavity of the pressure regulating valve core and a spring assembly. The invention has the advantages of fulfilling the functions of a balance valve and also having the characteristics of a safety valve, realizing overflow from the oil port B to the oil port T by the secondary pressure overflow mechanism as well as overload protection of the valve, ensuring that the medium pressure in equipment and the medium pressure in a pipeline are within regulated values and preventing accidents from occurring.