Liver resection is the main way for the treatment of liver tumor, but hemorrhage during operation is always affecting the operation directly. How to control the liver bleeding during laparoscopic surgery is a long-term problem. Combining with the clinical practical application, a laparoscopic portal blood flow blocking device was designed. By controlling the airbag's contraction and expansion to control the blocking and patency of blood flow during the operation, the efficiency of operation was effectively improved. The fluid channel was divided into tetrahedral meshes by ANSYS. At the speed of 2, 4, 6, 8, 10 m/s, a finite element analysis of the air flow at the outlet of the airbag was carried out. By comparing the velocity vectors diagrams, at the speed of 8 m/s, the distribution of gas is the most gentle, the internal pressure distribution is more uniform and the flow can be provided most efficiently.