Improved substrate capable of improving soil properties and preparation method thereof

The invention provides a preparation method of an improved matrix capable of improving soil properties. The preparation method comprises the following steps that (1), flaccid knotweed herb and sasangua cake are weighed in parts by weight, an ethanol water solution is added, heating, decocting, cooling and filtering are carried out to obtain a filtrate, and a plant mixed solution is obtained; (2), the filtered flaccid knotweed herb and tea seed cake filter residues in the step (1) are weighed, aired, chopped and ground to obtain flaccid knotweed herb mixed powder; (3), charcoal, kaolin, an organic fertilizer, wormcast and weathered coal are weighed, uniformly mixed and ground, the plant mixed solution prepared in the step (1) and the flaccid knotweed herb mixed powder prepared in the step (2) are added for being uniformly mixed, blending is carried out to obtain a main material, the mixed microbial inoculum is uniformly spread on the main material, and primary fermentation is carried out; and (4), a water-reta