Cross-clamping the tube with two hemostatic forceps------refers to using two hemostatic forceps to clamp the drainage tube. The specific clamping method is to clamp the adjacent tube with two hemostatic forceps. Two places play an exact sealing role to prevent one hemostatic forceps from loosening, and another one can ensure the sealing of the drainage tube. Prevent gas and liquid in the drainage bottle from flowing back into the chest cavity due to poor sealing.