The invention discloses a wind power converter based on a bipolar direct-current structure. The wind power converter comprises a machine side converter and a net side converter which are connected. The wind power converter is characterized in that the machine side converter is composed of at least two controllable rectification circuits which are connected with a cascade wind generating set at an alternating current input side, three-phase alternating currents output by the cascade wind generating set are converted into bipolar direct currents to be output, and bipolar direct-current outputs are connected in series at a first series-connection point at a direct-current output side and then are connected to the ground. The net side converter is composed of at least two controllable inversion circuits, the bipolar direct currents output by the machine side converter are converted into three-phase alternating currents to be output, bipolar direct-current inputs are connected in series at a second series-connection point on a direct-current input side and then are connected to the ground, and an alternating-current output side is divided into two circuits to be connected to a double three-phase input winding grid connection transformer. According to the wind power converter, loop currents generated by parallel connection of converters are reduced, cable losses are reduced, and cost is greatly reduced.