Round steel threading machine with power gear transmission device

A round steel threading machine with a power gear transmission device comprises the power gear transmission device. The power gear transmission device comprises gear case body, and a motor gear, a high-speed gear group, a low-speed gear group and an output gear are respectively arranged inside the case body, wherein the motor gear, the high-speed gear group, the low-speed gear group and the output gear are all connected with a motor shaft. The gear shaft of the motor gear is arranged inside the case body through an input bearing, the shaft hole of the gear shaft is fixedly connected with the motor shaft, and a sealing ring is sleeved on the side of the case body of the gear shaft. The motor gear is meshed with a high-speed big gear of the high-speed gear group, a high-speed small gear which is coaxial with the high-speed big gear is meshed with a low-speed big gear, a low-speed small gear which is coaxial with the low-speed big gear is meshed with an output gear, and an output gear shaft extending out of the