Abstract: A rubber airbag plays a very important role in the pipeline plugging devices. In order to improve its overall performance, a 3D model of rubber airbag was established based on its working principle and working environment. Based on the finite element analysis software ANSYS, the rubber airbag was improved correspondingly by combining various analysis methods together, e.g. structural static mechanics analysis, contact analysis and test design. The plugging pressure of the airbag before and after the improvement were compared. It is shown that after the airbag is improved, its plugging pressure is increased by 50.1% and can reach 1.126 MPa. Besides, the test results were compared with ANSYS simulation results. It is indicated that the numerical simulation results are consistent with the experimental results, demonstrating the accuracy of analysis results by the finite element model. The design not only provides a new idea for the optimization of pipeline plugging devices, but also facilitates the construction of the reliability evaluation system for pipeline plugging devices.