The invention provides a soil improvement method which is characterized by the following steps: strip ridges which are formed by stacking and retting of animal waste, straws, crop bran and the like are fermented, wherein the cross sections of the strip ridges are trapezoid, and fermented substrate is obtained; earthworms are bred so that earthworm waste is obtained, and the earthworm waste is separated, collected, dried and smashed; and the earthworm waste is spread, wherein the dosage of the spread earthworm waste is not less than 600 kg / mu. Due to the fact that the earthworm waste contains a lot of major elements, such as nitrogen, phosphorus and potassium, needed by plants, and is rich in 18 types of amino acid which is not contained in normal animal waste, 5 types of biological active enzyme and a lot of microelements such as copper, zinc, manganese, iron, selenium, calcium and magnesium, by means of the ion exchange theory and salt transformation theory, and by the mutual combination of a quick effect and a slow effect, soil hardening and physicochemical shape of salt and alkali can be improved, potential of hydrogen (pH) value and salt content can be reduced, fertility of soil can be improved, and alkali changing and fertility fostering are integrated. Due to the fact that the raw materials are wide in source, production cost is easy to control, the soil improvement effect is good, crops can grow very well and income of farmers can be improved.