The purpose of this study is to examine the role of airflow on fiber’s strength under different inlet pressure. A two-parameter numerical mathematic model is developed to describe the airflow in splicing chamber. The simulations are validated against the experimental results regarding fiber’s strength. The flow field survey show that the swirling flow in chamber play a significant role in fiber’s splicing. The strength of splicing fiber is determined by two characteristics of flow, namely, vortices and pressure gradients which both were affected by inlet pressure. When the inlet pressure keep low, the strength of fiber is dominated by vortices of flow, otherwise, pressure gradients push fibers to wall quickly so fibers can not intermingle with each other completely.