The invention discloses a production method of modified starch for seasoning sauce and the sauce. The production method includes the following steps that first, tapioca starch and water are mixed andstirred well; second, 3% of dilute sodium hydroxide is added to adjust the pH to be 9.2-9.5, the temperature is adjusted to 40 DEG C, and 0. 5% of sodium hypochlorite is added for a reaction; third, apH value is adjusted to be 10.5, the temperature is reduced to 20 DEG C, then epoxypropane is added, the pH is adjusted to be 11-12, and a reaction is conducted for 36 hours; fourth, the temperatureis risen to 85 DEG C, dilute acid is added to adjust the pH to be 10.5-11, and then sodium trimetaphosphate is added; and fifth, finally, diluted hydrochloric acid is added to adjust the pH to be 5.6-5.8, and after swirl washing, the modified starch for the powder seasoning sauce is obtained by dewatering and drying. The modified starch provided by the invention is used for the sauce, thus the stability of the sauce is good, the sauce is not dehydrated or diluted after more than 5 times of cold-cut melting, and the good viscosity can still be maintained.