The invention discloses tetrahedral zinc oxide single-crystal particles and a preparation method thereof. The preparation method comprises the steps that anhydrous zinc acetate and octanol are mixed and are stirred evenly, a mixture of an ethyl alcohol stearate solution and lauryl amine is added into the mixture, and even mixing and stirring are performed to obtain a transparent solution. The transparent solution is heated to 140-145 DEG C under gas protection, and reflux reaction is performed at the temperature; after reaction is completed, centrifugal separation and washing are performed to obtain the tetrahedral zinc oxide single-crystal particles. The method is simple and easy in technological process, the reaction time is shorter, the obtained product has tetrahedral morphology, is simple in morphology and controllable in size, has the good application prospect in the fields of new energy resources and sensing and can also serve as an additive for high-end sunscreen skin care products.