Advancements in intracellular delivery have garnered significant attention due to their potential applications in the biological and medical fields. Traditional methods, including virus infection, electroporation, and lipofection, have limitations such as toxicity, high costs, and low delivery efficiency. This study presents a novel intracellular delivery method utilizing a stainless-steel filter combined with poly(ethylene oxide) (PEO) solution to transport biomolecules into cells. Optimal parameters were identified through systematic adjustments using fluorescein isothiocyanate (FITC)-dextran. The performance was further evaluated by mRNA encoding enhanced green fluorescent protein (eGFP), demonstrating a remarkable delivery efficiency of 94.7%, a cell viability rate of 94.3%, and a throughput of 1 × 107 cells/min. This new approach not only provides a cost-effective and user-friendly alternative but also enhances the potential for high-throughput applications in biological research and therapeutic interventions. The findings suggest that the integration of stainless-steel filters and viscoelastic fluids enhances intracellular delivery capabilities, positioning this method as a promising tool for advancing cellular engineering technologies.