Fuente: WIPO "processing tomato" The invention belongs to the technical field of dairy product processing, and particularly relates to additive-free natural fruity yoghourt and a preparation method thereof. The natural fruity yoghourt comprises the following raw materials in percentage by mass: 80-92% of raw milk, 5-9% of sugar, 0.01-0.03% of a leavening agent and the balance of water, wherein the total mass of the raw milk, the sugar and the leavening agent is 100%; wherein the fermentation agent is a Dangxiong LB VIII bacterial agent of the lactobacillus delbrueckii subsp. Lactis (Dangxiong LB VIII). No food additive, jam and fruit juice are added into the formula of the yoghourt, so that the yoghourt conforms to the consumption trend of'nature, nutrition and health '; and the yoghourt product prepared by the method contains a flavor substance phenylacetaldehyde, so that the yoghourt is endowed with a pleasant and special fruit flavor and has a unique natural tomato flavor.