Flexible piezoelectric composite (FPC) materials with strong designability are increasingly utilized in vibration control and structural health monitoring. The sensing and actuating performances of FPCs are directly affected by the several parameters, such as ceramic fiber volume fraction, flexible interdigitated electrode width, electrode spacing, and component thicknesses. These parameters should be optimized in order to make the tradeoff between the sensing-actuation performance and the compliance. This study systematically explored the relationships between material properties (such as electrostrain coefficients, dielectric coupling coefficients, and compliance matrix) and component parameters. A representative volume element (RVE) model at the microscale was employed to investigate the electric field distribution and sensing/actuation effects of FPCs with varying parameter configurations under voltage excitation. This analysis identified optimal component parameter ratios for FPCs, providing a theoretical foundation for their design and fabrication. The study concluded that an FPC with a ceramic fiber volume fraction of 75 %, electrode spacing of 0.1 mm, and electrode width of 0.01 mm achieves optimal sensing and actuation performance while maintaining good compliance. This research offers valuable insights for the development of flexible piezoelectric composites with tailored properties for advanced applications.