The invention discloses a method for reinforcing a soft foundation through electrochemistry-vacuum preloading. The method comprises the steps that firstly, electrochemical grouting is adopted to enable a sodium carbonate solution and a calcium chloride solution to form cemented crystals, and fine clay particles are cemented to be large particles; and secondly, drainage consolidation is conducted by combining vacuum preloading. According to the method for reinforcing the soft foundation through electrochemistry-vacuum preloading, the fine clay particles are changed to be large clay particles byprecipitating the calcium carbonate crystals, the permeability of a soil mass is improved, and the drainage effect of vacuum preloading is improved; a chemical solution is injected into low-permeability soft foundation soil by adopting an electron-osmosis method, permeating of the chemical solution is promoted, the chemical reaction between the chemical solution and the soft foundation soil is accelerated, the sizes of the soil particles can be evenly and sufficiently changed, and the soil mass strength is evener after the soil mass is reinforced; and a grouting material is green and economical, the precipitated calcium carbonate crystals are green and harmless, the material utilization rate is high, and the handling expense of the soil foundation soil is effectively saved.