The invention discloses a coulomb electric precipitator which comprises a dedusting tank body, wherein the two ends of the dedusting tank body are provided with an air inlet tank and an air outlet tank; one side, which is adjacent to the air inlet tank, of the dedusting tank body is provided with a front electric field which comprises fixed polar plates and corona discharge electrodes; the fixed polar plates and the corona discharge electrodes are arranged alternately; the fixed polar plate is provided with fixed polar plate air vents through which smoke passes; an electric field channel is formed between adjacent fixed polar plates; a rear electric field comprises movable polar plates and the corona discharge electrodes, and the movable polar plates and the corona discharge electrodes are arranged alternately; the movable polar plates are connected with an elevator mechanism for driving the movable polar plates to move up and down; rotary brushes are arranged below the movable polar plates, and the corona discharge electrodes are provided with negative electrode rappers; ash buckets are arranged below the rotary brushes; and the movable polar plates are provided with movable polar plate air vents through which the smoke passes, and an electric field channel is formed between adjacent movable polar plates. The Coulomb electric precipitator can effectively prevent secondary dust flying in the dedusting process, maintains stable and high dedusting efficiency and lowers the cost.