The invention discloses a making method of low-alcoholic-strength potato Baijiu. In the test, potatoes, tartary buckwheat shells, rice bran, glucoamylase and distiller's yeast are used as raw materials; the distilled Baijiu making process is used; the influence of five factors including the potato and tartary buckwheat shell ratio, the glucoamylase addition quantity, the distiller's yeast additionquantity, the fermentation time and the stirring time on the low-alcoholic-strength potato Baijiu making test process on the alcoholic strength and the sensing evaluation is studied and analyzed; thetest result shows that a good product can be obtained under the conditions of the total quantity of the potatoes and tartary buckwheat shells being 1000g, the potato and tartary buckwheat shell ratiobeing 8:2, the distiller's yeast addition quantity being 1.40 percent, the glucoamylase addition quantity being 0.40 percent, the fermentation time being 24d, the stirring time being 24h; the beneficial technical guidance is provided for the low-alcoholic-strength potato Baijiu making production technology in future.