The invention provides a flexible DC distribution network integrated protection system. The system comprises: a current signal input module, comprising eight paths of signal input ends used for collecting six paths of bridge arm currents, positive electrode DC current and negative electrode DC current; a field programmable gate array communicating with the current signal input module and synchronously acquiring the current values of the bridge arm current, the positive electrode DC current and the negative electrode DC current, and transmitting the current values to the ARM processor at regular intervals, wherein the field programmable gate array is used for generating an outlet control command according to the current values, and transmitting the outlet control command to the valve-basedcontroller; the valve-based controller for controlling lock-up and trip of the converter valve; and an ARM processor that communicates with the in-station monitoring system, communicates with the field programmable gate array and shares the stored information. By use of various embodiments of the present application, fast and accurate protection control of the bridge arm and inter-pole short circuit faults of the flexible DC distribution network converter station can be achieved.