Institute of Plasma Physics of Chinese Academy of Science(ASIPP) is responsible for developing, assembling, and testing Poloidal Field(PF) Converter units in the International Thermonuclear Experimental Reactor(ITER). Based on CODAC(Control, Data Access and Communication), provided by ITER Organization(IO). This paper completes the design of ITER poloidal field(PF) Converter System’s Master Control System(MCS), makes it possible for six local control units of PF Converter System to transmit information to each other, data archive and alarm, and real-time control, and satisfies the demand to control the system in a control cycle(1 millisecond). This paper provides solutions to some key problems in MCS of PF Converter System, such as high-speed communication, real time control, and stability and reliability. This system also has been successfully tested in ITER PF prototype and ITER PF sequential in series test platform.