An infusion device includes an infusion pump and an infusion tube assembly. The infusion tube assembly includes a first tube body connected to the infusion pump, a tube joint structure having first, second and third tube joints, a second tube body, and a clamping device on the second tube body. The clamping device is to clamp the second tube body. An infusion method includes instructing the infusion pump to perform an infusion operation. When bubbles are detected in a liquid in the infusion tube assembly, the infusion pump is instructed to stop the infusion operation and a bubble alarm is generated. After the infusion pump stops the infusion operation, it is determined whether a pressure of the liquid first drops to a first pressure value and then rises to a second pressure value. If yes, a rinsing operation is performed.