The invention provides an on-line aseptic adding device and method for granular additives in liquid food. The device is characterized in that an aseptic bag is provided with a reserved compressed air opening and a reserved discharging outlet; the reserved discharging outlet makes contact with one end of an abutting pipeline, and the other end of the abutting pipeline is provided with a first aseptic valve; a first steam valve and a second steam valve are both arranged on the abutting pipeline; the abutting pipeline communicates with an aseptic pipeline through an intermediate pipeline, a second aseptic valve is arranged in the communicating position of the abutting pipeline and the intermediate pipeline, and a third aseptic valve is arranged in the communicating position of the intermediate pipeline and the aseptic pipeline; a third steam valve and a fourth steam valve are both arranged on the intermediate pipeline. According to the on-line aseptic adding device and method for the granular additives in the liquid food, on-line pipeline automatic cleaning is adopted, high-temperature sterilizing is conducted through steam, automatic adding is conducted in an aseptic environment, and the cleaning effect and the sterilization effect are good; in addition, the automation degree is high, and the equipment structure and the process method thereof are scientific in design and convenient to operate; aseptic on-line adding of fun beads can be achieved, when the device is applied, the breakage rate of the fun beads is low, and the forming degree of the fun beads is good.