The invention discloses a starch-based material with a cold water soluble characteristic and a preparation method thereof. The material comprises the following components in parts by weight: 100 of modified starch; 48 to 65 of PVA (Polyvinyl Alcohol), 22 to 50 of a composite plasticizer, 3 to 10 of pullulan, 5 to 10 of crosslinked starch and 1 to 3 of a processing aid. According to the invention,the composite efficient plasticizer is used for carrying out plasticization on a preparation system of the starch-based material, an amides modified water soluble polyatomic alcohol derivative is usedas one of composite plasticizers, the additive amount of the conventional plasticizer can be increased to 20% or more, and the plasticizer cannot be separated out, so that plasticization efficiency for starch and PVA is greatly improved; and meanwhile, water solubility of the starch and PVC composite material can also be improved, and the thermoplastic starch-based material which can be stably processed and has the cold water soluble characteristic is prepared. After the material prepared by the preparation method is subjected to extrusion blow molding to form a film, completely dissolved time of the thin film (20 to 50 mum) formed by the material in cold water (23 DEG C) is smaller than or equal to 180s.