The invention relates to the technical field of crop planting, and discloses a plant fermentation extract for improving rice planting soil and a preparation method of the plant fermentation extract. The plant fermentation extract for improving the rice planting soil is characterized by being prepared from cortex lycii radicis, tricholoma matsutake, pollen, radix sophorae flavescentis, dried lumbricus, hirudin, liquorice, cyrtomium fortunei, rhizoma phragmitis, pericarpium citri reticulatae, bamboo leaves, shredded coconut stuffing, hippophae rhamnoides, radix bupleuri, echinopsis tubiflora flower, salicornia europaea, fritillary bulb,radix glehniae, fructus aurantii, fructus evodiae, lentils, astragalus, amomum tsao-ko, selenium yeast, iron enriched yeast, rice germ, hemp seed and red ginseng, adopted as raw materials, are mixed according to a certain weight ratio, and the mixture is fermented, extracted and ground into powder. The raw materials are easy to obtain, the preparation process is simple, the soil structure is effectively improved, the number and activity of effective microorganisms in soil are increased, the soil enzyme content is increased, rice growth, yield increaseand quality improvement are facilitated. The method is suitable for wide application and popularization.