Abstract: Disclosed is a soil conditioner, comprising the following components in parts by weight: 10-20 parts of distiller's grains; 1-10 parts of cow dung; 1-10 parts of vermicompost; 1-10 parts of oil cake; 10-20 parts of dregs of decoction; 20-40 parts of fallow soil; and 20-40 parts of river sand. Also disclosed is a method for preparing a soil conditioner, comprising: first, separately fermenting distiller's grains, cow dung, vermicompost, oil cake, and dregs of decoction, and then mixing them with river sand and fallow soil for secondary solid fermentation to obtain the soil conditioner. The present invention has a remarkable restoration effect on obstructive soil, the microbial diversity index of the restored soil is increased, the microbial ecological structure of the soil is improved, and the quality of crops is enhanced.