Abstract: Battery separators as the key component of energy storage device is crucial for determining the safety and lifespan of batteries. This study introduces an innovative "blow molding-extraction" process for high performance separator development, which effectively integrates key steps, including melt mixing, extrusion blow molding, gas inflation, longitudinal stretching, and cooling. Firstly, by adjusting the component ratios and selecting appropriate pore-forming agents, separators with a porosity of 63% and a liquid absorption rate of 115% were produced. Furthermore, the introduction of the extraction process resulted in a uniform microporous structure that significantly enhanced the ionic transport efficiency of the electrolyte, yielding an ionic conductivity of 0.23 mS·cm-1. The assembled battery demonstrated a discharge specific capacity of 166.58 mAh·g-1 at a 0.1 C rate and maintained a coulombic efficiency of 96.11% after 25 cycles. These findings suggest that the "blow molding-extraction" process not only improves the overall performance of the separator but also provides a novel technological pathway for manufacturing high-end lithium battery separators, showcasing significant academic value and application potential. This method establishes a solid foundation for future advancements in battery technology and fosters further research and applications within the domain of electrochemical energy storage.