The invention discloses a method for improving the carbon steel solidification structure by adopting high voltage electrical pulse. The method is that in a continuous casting tundish and a continuous casting mould or a moulded casting mould, a selected high voltage electrical pulse is applied to the carbon steel solidification process or before carbon steel solidifying; the high voltage electrical pulse has the following parameters: the pulsed voltage is from 1000V to 3900V, the pulse rate is from 0.50Hz to 1.5Hz, and the pulse capacitor is from 100 microfarad to 500 microfarad. The method isespecially suitable for steel grades to improve large coarse grains in the solidification structure, developed dendrite and easy generation of composition segregation, can increase the nucleation rate of metal solidification, reduce dendrite, increase equiaxed grains, reduce the internal cracks, the shrinkage holes and the loose of the solidification structure, and improve the composition segregation; and the mechanical properties of the processed steel are improved.