The invention discloses a Hami melon/sea buckthorn brandy and a preparation method thereof. The preparation method comprises the following steps: adding sea buckthorn juice into Hami melon juice to prepare a fermentation substrate with the pH value of 3.7-3.9; inoculating Saccharomyces cerevisiae into the fermentation substrate, and fermenting; distilling the fermented raw wine twice to obtain a 60-65 %vol wine body used as unblended wine; adding fruit pomace into the foreshot and feint, carrying out steam distillation, and collecting the early-stage distillate as blending wine; and adding the blending wine into the unblended wine, and aging to obtain the Hami melon/sea buckthorn brandy with pleasant flavor. The Hami melon/sea buckthorn brandy has harmonized fruit and vinous aroma and outstanding melon aroma, and thus, has abundant and complex aroma; and the wine body is complete, smooth, thick and plump. By fully utilizing the high acidity and abundant VC and flavones of the sea buckthorn, the acidity, bacterial resistance and oxidation resistance of the fermentation substrate of the improved Hami melon brandy raw wine are enhanced, the quality of the raw wine is improved, the storage period is prolonged, and the safety in the storage period is enhanced.