The invention discloses a preparation method for a yeast extract with a vegetable flavor and a product thereof. The method comprises the following steps: 1) adding a reaction raw material which contains the yeast extract and a vegetable extract to a reaction kettle; and 2) performing thermal reaction processing on the reaction raw material in the reaction kettle, wherein the reaction temperature is of between 105 and 135 DEG C; and the reaction time is between 15 and 60 minutes. In the method, the reaction raw material containing the yeast extract and the vegetable extract is subjected to thethermal reaction processing technology, which improves the aroma and the mouthfeel of the yeast extract, and improves a characteristic aroma and an application effect; and the obtained yeast extract is added to various dishes and stuffing so as to effectively improve the mouthfeel of end products, enhance a local flavor, and improve a nutritive value. The preparation method has the advantages that the obtained yeast extract contains no meat component, but has stronger aroma and mouthfeel at the same time, so the yeast extract can be used in vegetarian foods.