The utility model discloses a braking mechanism for avoiding zero drift of an electrical positioner. The braking mechanism is arranged in a box cavity of the electrical positioner, a feedback rod stretches into the box cavity and is fixedly connected with a copper-made friction plate, and a reset spring abuts against the portion between the wall of the box cavity and the copper-made friction plate. The copper-made friction plate makes frictional contact with a plastic variable resistance connecting rod to rotate the plastic variable resistance connecting rod. A lock nut is connected to a rotating shaft connected with the plastic variable resistance connecting rod in a screwing mode, and a spring disc abuts against the portion between the lock nut and the plastic variable resistance connecting rod. According to the braking mechanism, the copper-made friction plate and the plastic variable resistance connecting rod are made to move together, so that zero drift of the electrical positioner caused by decrease of friction force of the copper-made friction plate and the plastic variable resistance connecting rod is avoided.