The invention relates to preparation of a compound fruity birch liquid syrup, and belongs to the technical field of food processing. The preparation is characterized by comprising selecting the birchliquid collected on the day, sterilizing the birch liquid and adding the sterilized birch liquid into a vacuum concentrator for concentration to obtain a birch liquid concentrated solution, mixing four kinds of wild fruits, such as rosa davurica, malus pallasiana, aronia melanocarpa elliott and actinidia kolomikta planch, at a weight ratio of 1:1:2:2, then treating the mixture with a colloid milland a homogenizer, centrifuging and filtering for 8-10 minutes to obtain a composite juice, sterilizing the composite juice and adding the juice into the vacuum concentrator for concentration to obtain a compound juice concentrate; adding the birch liquid concentrate and the composite juice concentrate as per the weight ratio of 5:1 and stirring for 12 minutes, then adding the concentrate to the vacuum concentrator again for concentration till the volume is reduced by 50 times to obtain the composite fruity birch liquid syrup. The syrup is concentrated for multiple times at different low temperatures, and has better stability, flavor and taste. Nutritional ingredients do not contain any preservative.