The invention discloses an electric pole pit groove digging device. The electric pole pit groove digging device comprises a frame, a rotating disc rotatably connected to the frame, a lifting mechanismconnected to the rotating disc, a digging knife assembly connected to the lifting mechanism for digging a pit groove, a counterweight assembly fixedly arranged at the rear portion of the frame and used for balancing the weight of the lifting mechanism, and a travelling mechanism arranged below the frame. According to the electric pole pit groove digging device, a pole carrying pit is excavated through mechanical automation, time and labor are saved, the construction efficiency is high, the depth of the pit groove is convenient to control, the stability consistence of carried poles is high, aposition sensor is used for aligning the front electric pole and the rear electric pole, the carried poles are guaranteed to be in a straight line, and the interval distance among the electric poles is measured and adjusted through an infrared distance sensor, so that the direction accuracy of a power transmission line is improved, and the running stability of the power transmission line is guaranteed.