This study introduces a novel droplet microfluidic chip that enhances single-cell encapsulation by integrating a double spiral focusing unit and an on-chip sample enrichment module. The chip enables efficient focusing of cells and beads into a linear arrangement, followed by the removal of excess aqueous phase to increase sample concentration. This approach allows for higher encapsulation rates and reduces the need for high cell densities, which can cause clogging in narrow channels. The sample enrichment module uses flow resistance to adjust the amount of aqueous phase removed, with the number of serpentine units determining the extent of removal. The chip was tested with polystyrene beads and cancer cell lines, achieving encapsulation rates of 79.2% for beads and 72.2% for cells. The study demonstrates that the on-chip enrichment method significantly improves the efficiency and flexibility of single-cell encapsulation in water-in-oil droplets. The results show that the optimal cell concentration for efficient encapsulation is around 2 × 10⁶ cells/mL, with higher concentrations leading to increased multiple-cell encapsulation. The chip's design allows for adjustable flow resistance, enabling precise control over sample concentration and encapsulation efficiency. This innovation has potential applications in single-cell sequencing, cell lineage tracing, and rare cell analysis. The study highlights the importance of optimizing focusing and enrichment parameters to achieve high-efficiency single-cell encapsulation. The results suggest that the chip can be further refined to enhance performance and expand its applicability in various biological and medical research areas.This study introduces a novel droplet microfluidic chip that enhances single-cell encapsulation by integrating a double spiral focusing unit and an on-chip sample enrichment module. The chip enables efficient focusing of cells and beads into a linear arrangement, followed by the removal of excess aqueous phase to increase sample concentration. This approach allows for higher encapsulation rates and reduces the need for high cell densities, which can cause clogging in narrow channels. The sample enrichment module uses flow resistance to adjust the amount of aqueous phase removed, with the number of serpentine units determining the extent of removal. The chip was tested with polystyrene beads and cancer cell lines, achieving encapsulation rates of 79.2% for beads and 72.2% for cells. The study demonstrates that the on-chip enrichment method significantly improves the efficiency and flexibility of single-cell encapsulation in water-in-oil droplets. The results show that the optimal cell concentration for efficient encapsulation is around 2 × 10⁶ cells/mL, with higher concentrations leading to increased multiple-cell encapsulation. The chip's design allows for adjustable flow resistance, enabling precise control over sample concentration and encapsulation efficiency. This innovation has potential applications in single-cell sequencing, cell lineage tracing, and rare cell analysis. The study highlights the importance of optimizing focusing and enrichment parameters to achieve high-efficiency single-cell encapsulation. The results suggest that the chip can be further refined to enhance performance and expand its applicability in various biological and medical research areas.