The invention relates to a basil seed suspension beverage and a preparation method thereof, and belongs to the food field, especially the field of beverage processing method. Each 250 mL of basil seed suspension beverage contains the following raw materials by weight: 0.5 to 1.5 grams of basil seed, 0.1 to 1.0 gram of suspending agent, 0.3 to 0.5 gram of critic acid, 0.1 to 0.2 gram of sodium citrate, 16.0 grams of white sugar, 0.1 gram of potassium sorbate, and 250 mL of water. The preparation method has the advantages of simple technology, strong operability, and suitability for industrial production. The sensory indexes of the beverage are good, and the basil seeds are evenly dispersed in the suspension beverage.