The invention relates to the technical field of power distribution protection, and discloses a power distribution network relay protection device. The power distribution network relay protection device comprises a central processing unit, an abnormal signal acquisition module, a 4G transmission module, a signal processing module, a protection execution module and an alarm module, wherein the inputend of the central processing unit is connected with the output end of the abnormal signal acquisition module separately; the output end of the signal processing module is electrically connected withthe output end of the protection execution module; the output end of the central processing unit is electrically connected with the input end of the abnormal signal acquisition module, the input endof the signal processing module, the input end of the protection execution module and the input end of the alarm module separately; and the output end of the abnormal signal acquisition module is in signal connection with the input end of the 4G transmission module. The power distribution network relay protection device is provided with the abnormal signal acquisition module, the signal processingmodule and the protection execution module, so that the relay protection device is divided into three parts, and independent operation and mutual control are carried out respectively, so that the relay protection device is clear and reasonable in structure and convenient in performing overall management.\