The invention belongs to the technical field of medication and particularly relates to a composition used for preparing soft capsules of plants and an application of the composition. The composition comprises hydroxypropyl starch acetate, a gelatinizing agent, a thickening agent and water by mixing. Due to the introduction of acetyl groups in hydroxypropyl starch acetate, good compatibility of thehydroxypropyl starch acetate with a plant material polysaccharide gelling agent is achieved, even the synergistic function can be generated, gel rubber with high toughness can be obtained during thesol-gel process of the composition, material cost is reduced, efficiency in production of the soft capsules of plants and product quality are guaranteed, and the production of the soft capsules of theplants with the composition has economic benefits and popularization value.