The invention discloses a safety device for preventing people from climbing up electric concrete poles by mistake, which comprises a locking ring tightly sleeved on the periphery of an electric concrete pole, wherein the locking ring comprises a fixed semi-ring and a movable semi-ring correspondingly arranged at the two sides of the electric concrete pole, the fixed semi-ring and the movable semi-ring are respectively provided with a lock device for tightly clamping the inner wall of the fixed semi-ring as well as the inner wall of the movable semi-ring and the outer wall of the electric concrete pole together, and support arms extending outwards are uniformly distributed on the outer wall of the locking ring; conical bulges are uniformly distributed on the periphery of each support arm; and an end of each support arm far away from the locking ring is fixedly provided with a spring. The safety device for preventing people from climbing up electric concrete poles by mistake, which adopts the structure, is reasonable in structure, can prevent other people from clamping up the electric concrete pole, and can provide convenience for the maintenance personnel to clamp up the electric concrete pole; meanwhile, the safety device is convenient to operate, is suitable for various electric concrete poles and particularly suitable for wooden electric poles and concreting electric poles which are arranged in human settlements, and can effectively avoid the occurrence of electric shock accidents caused by that other people clamps up the electric concrete poles by mistake.